docs(builtin): fix some missing lines (#24759)

Some things got chopped off in the PR that removed method syntax examples.
These were all that I found.

1 files changed, 8 insertions, 0 deletions

diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 8e92ca4e1c..94e9223ee9 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -429,6 +429,8 @@ bufname([{buf}])                                                     *bufname()*
 		with a listed buffer, that one is returned.  Next unlisted
 		buffers are searched for.
 		If the {buf} is a String, but you want to use it as a buffer
+		number, force it to be a Number by adding zero to it: >vim
+			echo bufname("3" + 0)
 <		If the buffer doesn't exist, or doesn't have a name, an empty
 		string is returned. >vim
 			echo bufname("#")	" alternate buffer name
@@ -3676,6 +3678,9 @@ interrupt()                                                        *interrupt()*
 
 invert({expr})                                                        *invert()*
 		Bitwise invert.  The argument is converted to a number.  A
+		List, Dict or Float argument causes an error.  Example: >vim
+			let bits = invert(bits)
+<
 
 isdirectory({directory})                                         *isdirectory()*
 		The result is a Number, which is |TRUE| when a directory
@@ -5665,6 +5670,9 @@ reverse({object})                                                    *reverse()*
 		{object} can be a |List| or a |Blob|.
 		Returns {object}.
 		Returns zero if {object} is not a List or a Blob.
+		If you want an object to remain unmodified make a copy first: >vim
+			let revlist = reverse(copy(mylist))
+<
 
 round({expr})                                                          *round()*
 		Round off {expr} to the nearest integral value and return it