vim: Import v9.1.1591

* runtime(vim): Update base syntax, fix :map termination in :command RHS

Author: github-actions[bot]

gitlog.txt

@@ -1 +1 @@
-* [CI: Manage multibyte characters in syntax tests](https://github.com/vim/vim/commit/0fde6aebddef5cb0428e85040994ba45e55cba99)\n* [CI: Remove the file filters for syntax tests](https://github.com/vim/vim/commit/43b99c93769aa267db0cf3be7412547696990837)\n* [CI(screendump): Support iterative filtering for screendump comparison](https://github.com/vim/vim/commit/624b75a272ccb736a463a2271811644618c3f5ab)\n* [CI(screendump): Move an early-return test out of the loop](https://github.com/vim/vim/commit/64329714c7ea2b0520c5891f13dc00d1f8e2a41e)\n* [CI: Include provenance in names of collected artifacts](https://github.com/vim/vim/commit/25ea22439e8c24d43c2d373f175662f9b1b3f5db)\n* [runtime(vim): Cleanup syntax tests](https://github.com/vim/vim/commit/cced80dcbb07a3b07fbfdf74637327a38476bcbf)\n* [9.1.1591](https://github.com/vim/vim/commit/e9d1259111daf9c91b14c252047defc99c03a8de): VMS support can be improved\n* [9.1.1590](https://github.com/vim/vim/commit/af9a7a04f18693eee4400dd134135527f4e8cd5f): cannot perform autocompletion\n* [runtime(ccomplete): return partial results on complete\_check()](https://github.com/vim/vim/commit/44309b9d08ba657d8c2ee5ed614c14b0fa0cfefc)\n* [9.1.1589](https://github.com/vim/vim/commit/b124b8d276fd465bff78111113256b308f6a7f8d): Cannot disable cscope interface using configure\n* [9.1.1588](https://github.com/vim/vim/commit/a566a780297793b6a309ac4563bb17eedb83e6b0): Vim9: cannot split dict inside command block\n* [runtime(netrw): upstream snapshot v184](https://github.com/vim/vim/commit/0bda7830ac140d2a347fe81edc95314b020b7ca6)\n* [runtime(vim): fix various indentation issues](https://github.com/vim/vim/commit/827483054db32d0953abb9060355326ab9230175)
+* [runtime(vim): Update base syntax, fix :map termination in :command RHS](https://github.com/vim/vim/commit/b88f9e4a04ce9fb70abb7cdae17688aa4f49c8c9)