vim: Import v8.0.1608

* 8.0.1608: Win32: directx not enabled by default
* 8.0.1607: --clean loads user settings from .gvimrc
* 8.0.1606: singular/plural variants not translated

Author: chrisbra

gitlog.txt

@@ -1 +1 @@
-* [8.0.1605](https://github.com/vim/vim/releases/tag/v8.0.1605): terminal test is a bit flaky\n* [8.0.1604](https://github.com/vim/vim/releases/tag/v8.0.1604): paste test may fail if $DISPLAY is not set\n* [8.0.1603](https://github.com/vim/vim/releases/tag/v8.0.1603): cannot build with +terminal but without +menu\n* [8.0.1602](https://github.com/vim/vim/releases/tag/v8.0.1602): crash in parsing JSON
+* [8.0.1608](https://github.com/vim/vim/releases/tag/v8.0.1608): Win32: directx not enabled by default\n* [8.0.1607](https://github.com/vim/vim/releases/tag/v8.0.1607): --clean loads user settings from .gvimrc\n* [8.0.1606](https://github.com/vim/vim/releases/tag/v8.0.1606): singular/plural variants not translated