Problem:    'shellslash' works differently when sourcing a script again.
Solution:   Use the name from the script item. (closes vim/vim#10920)
https://github.com/vim/vim/commit/5a4fff4d948cd12a5cf5f637ad2c561815a77d8e

Problem:    Expand('<stack>') has trailing "..".
Solution:   Remove the "..". (closes vim/vim#6927)
https://github.com/vim/vim/commit/a810db3f17d477e057059c72062c08fd97bcea43

Problem:    Expand('<stack>') does not include the final line number.
Solution:   Add the line nuber. (closes vim/vim#6927)
https://github.com/vim/vim/commit/4f25b1aba050b85fa97ca2316aa04dd4b0b22530

Problem:    When a test fails it's often not easy to see what the call stack
            is.
Solution:   Add more entries from the call stack in the exception message.
https://github.com/vim/vim/commit/a5d0423fa16f18b4576a2a07e50034e489587a7d

Use docs from latest Vim.

Problem:    Vim9: script reload test is disabled.
Solution:   Compile a function in the context of the script where it was
            defined.  Set execution stack for compiled function.  Add a test
            that an error is reported for the right file/function.
https://github.com/vim/vim/commit/25e0f5863e9010a75a1ff0d04e8f886403968755

Omit stack_top_is_ufunc(): only used by Vim9 script.

Co-Authored-By: VVKot <volodymyr.kot.ua@gmail.com>

Problem:    Execution stack is incomplete and inefficient.
Solution:   Introduce a proper execution stack and use it instead of
            sourcing_name/sourcing_lnum.  Create a string only when used.
https://github.com/vim/vim/commit/1a47ae32cdc19b0fd5a82e19fe5fddf45db1a506

Omit test_debugger.vim: superseded by later patches.
Omit check_map_keycodes(): N/A.
Omit kword_test.c: N/A (converted to a unit test).

Mostly avoids including eval.h, ex_cmds2.h and ex_docmd.h in other
headers.