close #25416

The style change is mostly a regression.

Reverts #25858 d50274812b275edff58418b3d17868385599fc14

Problem:
Numerous Vim 8.1 patches are listed by `vim-patch.sh -l`.

Solution:
Mark the following patches as N/A:

obviated by $NVIM env var:
vim-patch:8.1.0049 shell cannot tell running in a terminal window
vim-patch:8.1.0050 $VIM_TERMINAL is also set when not in a terminal window

'termwinkey' is not supported by Nvim:
vim-patch:8.1.0072 use of 'termwinkey' is inconsistent

Nvim handles STOP signal via libuv:
vim-patch:8.1.0304 no redraw when using a STOP signal on Vim and then CONT
vim-patch:8.1.0312 wrong type for flags used in signal handlers

Nvim does not have `parse_queued_messages`:
vim-patch:8.1.0367 getchar(1) no longer processes pending messages

N/A various:
vim-patch:8.1.1396 'wincolor' does not apply to lines below the buffer
vim-patch:8.1.1502 cannot play any sound
vim-patch:8.1.1515 memory leak reported for sound when build with EXITFREE

Nvim has extmarks instead of textprops:
vim-patch:8.1.0579 cannot attach properties to text
vim-patch:8.1.0582 text properties are not enabled
vim-patch:8.1.0634 text properties cannot cross line boundaries
vim-patch:8.1.0638 text property highlighting is off by one column
vim-patch:8.1.0639 text properties test fails on MS-Windows
vim-patch:8.1.0643 computing byte offset wrong
vim-patch:8.1.0654 when deleting a line text property flags are not adjusted
vim-patch:8.1.0655 when appending a line text property flags are not added
vim-patch:8.1.0663 text property display wrong when 'number' is set
vim-patch:8.1.0665 text property display wrong when 'spell' is set
vim-patch:8.1.0667 textprop test leaves file behind
vim-patch:8.1.0675 text property column in screen columns is not practical
vim-patch:8.1.0676 textprop screendump test fails
vim-patch:8.1.0681 text properties as not adjusted for deleted text
vim-patch:8.1.0682 text properties not adjusted when backspacing replaced text
vim-patch:8.1.0688 text properties are not restored by undo
vim-patch:8.1.0689 undo with text properties not tested
vim-patch:8.1.0690 setline() and setbufline() do not clear text properties
vim-patch:8.1.0691 text properties are not adjusted for :substitute
vim-patch:8.1.0694 when using text props may free memory that is not allocated
vim-patch:8.1.0703 compiler warnings with 64-bit compiler
vim-patch:8.1.0707 text property columns are not adjusted for changed indent
vim-patch:8.1.0970 text properties test fails when 'encoding' is not utf-8
vim-patch:8.1.1035 prop_remove() second argument is not optional
vim-patch:8.1.1276 cannot combine text properties with syntax highlighting
vim-patch:8.1.1278 missing change for "combine" field
vim-patch:8.1.1333 text properties don't always move after changes
vim-patch:8.1.1337 get empty text prop when splitting line just after text prop
vim-patch:8.1.1341 text properties are lost when joining lines
vim-patch:8.1.1343 text properties not adjusted for Visual block mode delete
vim-patch:8.1.1340 attributes from 'cursorline' overwrite textprop
vim-patch:8.1.1351 text property wrong after :substitute
vim-patch:8.1.1359 text property wrong after :substitute with backslash
vim-patch:8.1.1387 calling prop_add() in an empty buffer doesn't work
vim-patch:8.1.1388 errors when calling prop_remove() for an unloaded buffer
vim-patch:8.1.1463 gcc warns for uninitialized variable

N/A Nvim has buf_attach instead of "listeners":
vim-patch:8.1.1320 it is not possible to track changes to a buffer
vim-patch:8.1.1321 no docs or tests for listener functions
vim-patch:8.1.1326 no test for listener with partial
vim-patch:8.1.1328 no test for listener with undo operation
vim-patch:8.1.1332 cannot flush listeners without redrawing, mix of changes
vim-patch:8.1.1335 listener callback is called after inserting text
vim-patch:8.1.1419 listener callbacks may be called recursively
vim-patch:8.1.1486 a listener change is merged even when it adds a line

N/A build issues:
vim-patch:8.1.0601 a few compiler warnings
vim-patch:8.1.0612 cannot use two global runtime dirs with configure
vim-patch:8.1.0684 warnings from 64-bit compiler
vim-patch:8.1.1344 Coverity complains about possibly using a NULL pointer
vim-patch:8.1.1376 warnings for size_t/int mixups
vim-patch:8.1.1414 alloc() returning "char_u *" causes a lot of type casts
vim-patch:8.1.1508 sound keeps failing on Travis
vim-patch:8.1.1494 build failure

N/A terminal / job control patches:
vim-patch:8.1.0761 default value for brief_wait is wrong
vim-patch:8.1.0824 SunOS/Solaris has a problem with ttys
vim-patch:8.1.0845 having job_status() free the job causes problems
vim-patch:8.1.0870 Vim doesn't use the new ConPTY support in Windows 10
vim-patch:8.1.0880 MS-Windows: inconsistent selection of winpty/conpty
vim-patch:8.1.0890 pty allocation wrong if using file for out channel
vim-patch:8.1.0906 using clumsy way to get console window handle
vim-patch:8.1.0909 MS-Windows: using ConPTY even though it is not stable
vim-patch:8.1.0928 stray log function call
vim-patch:8.1.0940 MS-Windows console resizing not handled properly
vim-patch:8.1.1028 MS-Windows: memory leak when creating terminal fails
vim-patch:8.1.1265 when GPM mouse support is enabled double clicks do not work
vim-patch:8.1.1267 cannot check if GPM mouse support is working

N/A encoding patches:
vim-patch:8.1.0879 MS-Windows: temp name encoding can be wrong
vim-patch:8.1.0895 MS-Windows: dealing with temp name encoding not quite right
vim-patch:8.1.0918 MS-Windows: startup messages are not converted
vim-patch:8.1.1090 MS-Windows: modify_fname() has problems with some 'encoding'

N/A platform patches:
vim-patch:8.1.1103 MS-Windows: old API calls are no longer needed

N/A Lua patches:
vim-patch:8.1.1019 Lua: may garbage collect function reference in use

N/A Nvim has floating windows instead of popup window:
vim-patch:8.1.1329 plans for popup window support are spread out
vim-patch:8.1.1364 design for popup window support needs more details
vim-patch:8.1.1391 no popup window support
vim-patch:8.1.1400 using global pointer for tab-local popups is clumsy
vim-patch:8.1.1399 popup windows not adjusted when switching tabs
vim-patch:8.1.0062 popup menu broken if a callback changes the window layout
vim-patch:8.1.1405 "highlight" option of popup windows not supported
vim-patch:8.1.1406 popup_hide() and popup_show() not implemented yet
vim-patch:8.1.1407 popup_create() does not support text properties
vim-patch:8.1.1410 popup_move() is not implemented yet
vim-patch:8.1.1402 "timer" option of popup windows not supported
vim-patch:8.1.1408 PFL_HIDDEN conflicts with system header file
vim-patch:8.1.1420 popup window size only uses first line length
vim-patch:8.1.1421 drawing "~" line in popup window
vim-patch:8.1.1422 popup_getoptions() not implemented yet
vim-patch:8.1.1423 popup windows use options from current window and buffer
vim-patch:8.1.1426 no test for syntax highlight in popup window
vim-patch:8.1.1427 popup window screenshot test fails
vim-patch:8.1.1428 popup_atcursor() not implemented yet
vim-patch:8.1.1429 "pos" option of popup window not supported yet
vim-patch:8.1.1430 popup window option "wrap" not supported
vim-patch:8.1.1431 popup window listed as "Scratch"
vim-patch:8.1.1432 can't build with eval feature
vim-patch:8.1.1438 some commands cause trouble in a popup window
vim-patch:8.1.1441 popup window filter not yet implemented
vim-patch:8.1.1442 popup windows not considered when the Vim window is resized
vim-patch:8.1.1443 popup window padding and border not implemented yet
vim-patch:8.1.1444 not using double line characters for popup border
vim-patch:8.1.1445 popup window border highlight not implemented yet
vim-patch:8.1.1446 popup window callback not implemented yet
vim-patch:8.1.1447 not allowed to create an empty popup
vim-patch:8.1.1448 statusline is sometimes drawn on top of popup
vim-patch:8.1.1449 popup text truncated at end of screen
vim-patch:8.1.1450 popup window positioning wrong when using padding or borders
vim-patch:8.1.1451 CTRL-L does not clear screen with a popup window
vim-patch:8.1.1452 line and col property of popup windows not properly checked
vim-patch:8.1.1453 popup window "moved" property not implemented yet
vim-patch:8.1.1455 popup_atcursor() not completely implemented
vim-patch:8.1.1459 popup window border looks bad when 'ambiwidth' is "double"
vim-patch:8.1.1460 popup window border characters may be wrong
vim-patch:8.1.1416 popup_getposition() not implemented yet
vim-patch:8.1.1493 redrawing with popups is slow and causes flicker
vim-patch:8.1.1496 popup window height is not recomputed
vim-patch:8.1.1499 ruler not updated after popup window was removed
vim-patch:8.1.1511 matches in a popup window are not displayed properly
vim-patch:8.1.1513 all popup functionality is in functions, except :popupclear
vim-patch:8.1.1517 when a popup changes all windows are redrawn
vim-patch:8.1.1518 crash when setting 'columns' while a popup is visible
vim-patch:8.1.1520 popup windows are ignored when dealing with mouse position
vim-patch:8.1.1521 when a popup window is closed the buffer remains
vim-patch:8.1.1522 poup_notification() not implemented yet
vim-patch:8.1.1495 memory access error
vim-patch:8.1.1497 accessing memory beyond allocated space

N/A already applied:
vim-patch:8.1.1226 {not in Vi} remarks get in the way of useful help text
vim-patch:8.1.1280 remarks about functionality not in Vi clutters the help

It is less error-prone than manually defining header guards. Pretty much
all compilers support it even if it's not part of the C standard.

We already have an extensive suite of static analysis tools we use,
which causes a fair bit of redundancy as we get duplicate warnings. PVS
is also prone to give false warnings which creates a lot of work to
identify and disable.

refactor!: `vim.lsp.inlay_hint()` -> `vim.lsp.inlay_hint.enable()`

Problem:
The LSP specification allows inlay hints to include tooltips, clickable
label parts, and code actions; but Neovim provides no API to query for
these.

Solution:
Add minimal viable extension point from which plugins can query for
inlay hints in a range, in order to build functionality on top of.

Possible Next Steps
---

- Add `virt_text_idx` field to `vim.fn.getmousepos()` return value, for
  usage in mappings of `<LeftMouse>`, `<C-LeftMouse>`, etc