vim: Import v8.1.0952

* 8.1.0952: compilation warnings when building the MS-Windows installer
* 8.1.0951: using WIN64 even though it is never defined
* 8.1.0950: using :python sets 'pyxversion' even when not executed
* 8.1.0949: MS-windows defines GUI macros different than other systems
* 8.1.0948: when built without +eval "Vim --clean" produces errors
* 8.1.0947: using MSWIN before it is defined
* Revert change accidentally included in runtime file updates. Closes #3998.

gitlog.txt

@@ -1 +1 @@
-* [8.1.0946](https://github.com/vim/vim/releases/tag/v8.1.0946): Coveralls is not very useful\n* Update runtime files.\n* [8.1.0945](https://github.com/vim/vim/releases/tag/v8.1.0945): internal error when using pattern with NL in the range\n* [8.1.0944](https://github.com/vim/vim/releases/tag/v8.1.0944): format of nbdbg() arguments is not checked\n* [8.1.0943](https://github.com/vim/vim/releases/tag/v8.1.0943): still a trace of Farsi support\n* [8.1.0942](https://github.com/vim/vim/releases/tag/v8.1.0942): options window still checks for the multi_byte feature\n* [8.1.0941](https://github.com/vim/vim/releases/tag/v8.1.0941): macros for MS-Windows are inconsistent\n* [8.1.0940](https://github.com/vim/vim/releases/tag/v8.1.0940): MS-Windows console resizing not handled properly\n* [8.1.0939](https://github.com/vim/vim/releases/tag/v8.1.0939): no completion for sign group names\n* [8.1.0938](https://github.com/vim/vim/releases/tag/v8.1.0938): background color is wrong in MS-Windows console\n* [8.1.0937](https://github.com/vim/vim/releases/tag/v8.1.0937): invalid memory access in search pattern
+* [8.1.0952](https://github.com/vim/vim/releases/tag/v8.1.0952): compilation warnings when building the MS-Windows installer\n* [8.1.0951](https://github.com/vim/vim/releases/tag/v8.1.0951): using WIN64 even though it is never defined\n* [8.1.0950](https://github.com/vim/vim/releases/tag/v8.1.0950): using :python sets 'pyxversion' even when not executed\n* [8.1.0949](https://github.com/vim/vim/releases/tag/v8.1.0949): MS-windows defines GUI macros different than other systems\n* [8.1.0948](https://github.com/vim/vim/releases/tag/v8.1.0948): when built without +eval "Vim --clean" produces errors\n* [8.1.0947](https://github.com/vim/vim/releases/tag/v8.1.0947): using MSWIN before it is defined\n* Revert change accidentally included in runtime file updates. Closes #3998.