vim: Import v9.1.1863

* runtime(vimcomplete): do not complete 'shellcmd' on WSL and Windows
* 9.1.1863: Cannot test for working "+" register
* 9.1.1862: wrong ifdefs for clipboard provider
* runtime(odin): fix indent for mis-identified case statements
* 9.1.1861: Amiga: Locating runtime dir and rc files can be simplified
* 9.1.1860: clipboard register "+" enabled with cplipboard provider feature
* 9.1.1859: completion: whitespace not cleared with 'ai'
* 9.1.1858: v:register not reset after Visual mode command

Author: github-actions[bot]

gitlog.txt

@@ -1 +1 @@
-* [9.1.1857](https://github.com/vim/vim/commit/67860efe5b8e5a8d2bf6169ebe3d9143837c55c4): Missing clipboard provider support\n* [9.1.1856](https://github.com/vim/vim/commit/1a09f11f5d96f169d40eb74c260a8520efd10558): cannot style popup window (border, shadow, etc)\n* [9.1.1855](https://github.com/vim/vim/commit/e15cd0f0656b84aa363d93545289aa1d4fe51925): Makefile: using non-portable syntax\n* [runtime(doc): Miscellaneous documentation fixes](https://github.com/vim/vim/commit/c95e14381956ed3282cce5ec1285e356fb3649ac)\n* [runtime(doc): Fix example highlighting at :help prop\_list()](https://github.com/vim/vim/commit/97da1ec67063c7f8413886e221a98a02e401054d)
+* [runtime(vimcomplete): do not complete 'shellcmd' on WSL and Windows](https://github.com/vim/vim/commit/30ff1e3b0274a40bc64025bf0eaca20f636e6414)\n* [9.1.1863](https://github.com/vim/vim/commit/f22cedd75fa30e046e96ace4b2f54d8dca601ed2): Cannot test for working "+" register\n* [9.1.1862](https://github.com/vim/vim/commit/18d57a1b4c31d2a0eca28a4ba13e6a6998fb0e75): wrong ifdefs for clipboard provider\n* [runtime(odin): fix indent for mis-identified case statements](https://github.com/vim/vim/commit/a30cf0b3ace613e216b7ae248b657b281de9f21c)\n* [9.1.1861](https://github.com/vim/vim/commit/1c9135a362a1058f12c05d8496ff4ef0888f83d8): Amiga: Locating runtime dir and rc files can be simplified\n* [9.1.1860](https://github.com/vim/vim/commit/761a484e12fcdaf5d78293ce56d098ea6a39ba30): clipboard register "+" enabled with cplipboard provider feature\n* [9.1.1859](https://github.com/vim/vim/commit/6180d65751d8cc85460eb1729dd04815b9f14aa4): completion: whitespace not cleared with 'ai'\n* [9.1.1858](https://github.com/vim/vim/commit/b3b47e540d35742503ea372c5a97e8fb5681ab26): v:register not reset after Visual mode command