patch 9.1.0610: filetype: OpenGL Shading Language files are not detected

Problem:  filetype: OpenGL Shading Language files are not detected
Solution: detect various file extensions as GLSL filetype, include
          indent and syntax script, do no longer recognize '*.comp'
          as Mason filetype (Gregory Anders)

closes: #15317

Signed-off-by: Gregory Anders <greg@gpanders.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/.github/MAINTAINERS b/.github/MAINTAINERS
index c4cab55..7ec5433 100644
--- a/.github/MAINTAINERS
+++ b/.github/MAINTAINERS
@@ -306,6 +306,7 @@
 runtime/indent/gdscript.vim		@habamax
 runtime/indent/gitconfig.vim		@tpope
 runtime/indent/gitolite.vim		@sitaramc
+runtime/indent/glsl.vim		@gpanders
 runtime/indent/go.vim			@dbarnett
 runtime/indent/gyp.vim			@ObserverOfTime
 runtime/indent/haml.vim			@tpope
@@ -439,6 +440,7 @@
 runtime/syntax/gitignore.vim		@ObserverOfTime
 runtime/syntax/gitolite.vim		@sitaramc
 runtime/syntax/gitrebase.vim		@tpope
+runtime/syntax/glsl.vim		@gpanders
 runtime/syntax/go.vim			@bhcleek
 runtime/syntax/godoc.vim		@dbarnett
 runtime/syntax/gp.vim			@KBelabas