vim: Import v8.1.1108

* 8.1.1108: test for 'visualbell' doesn't work
* 8.1.1107: no test for 'visualbell'
* 8.1.1106: no test for 'writedelay'
* 8.1.1105: long escape sequences may be split up
* 8.1.1104: MS-Windows: not all environment variables can be used

gitlog.txt

@@ -1 +1 @@
-* [8.1.1103](https://github.com/vim/vim/releases/tag/v8.1.1103): MS-Windows: old API calls are no longer needed\n* [8.1.1102](https://github.com/vim/vim/releases/tag/v8.1.1102): Win32 exe file contains unused code\n* [8.1.1101](https://github.com/vim/vim/releases/tag/v8.1.1101): signals test may fail in the GUI\n* [8.1.1100](https://github.com/vim/vim/releases/tag/v8.1.1100): tag file without trailing newline no longer works
+* [8.1.1108](https://github.com/vim/vim/releases/tag/v8.1.1108): test for 'visualbell' doesn't work\n* [8.1.1107](https://github.com/vim/vim/releases/tag/v8.1.1107): no test for 'visualbell'\n* [8.1.1106](https://github.com/vim/vim/releases/tag/v8.1.1106): no test for 'writedelay'\n* [8.1.1105](https://github.com/vim/vim/releases/tag/v8.1.1105): long escape sequences may be split up\n* [8.1.1104](https://github.com/vim/vim/releases/tag/v8.1.1104): MS-Windows: not all environment variables can be used