patch 9.1.0325: filetype: CMakeCache.txt files not recognized

Problem:  filetype: CMakeCache.txt files not recognized
Solution: Detect 'CMakeCache.txt' files as cmakecache filetype,
          include basic syntax script for cmakecache
          (Wu, Zhenyu, @bfrg)

closes: #14384

Co-authored-by: bfrg <bfrg@users.noreply.github.com>
Signed-off-by: Wu, Zhenyu <wuzhenyu@ustc.edu>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/cmakecache.vim b/runtime/syntax/cmakecache.vim
new file mode 100644
index 0000000..f07c719
--- /dev/null
+++ b/runtime/syntax/cmakecache.vim
@@ -0,0 +1,60 @@
+" Vim syntax file
+" Language:     cmakecache - CMakeCache.txt files generated by CMake
+" Author:       bfrg <https://github.com/bfrg>
+" Upstream:      https://github.com/bfrg/vim-cmakecache-syntax
+" Last Change:  Nov 28, 2019
+" License:      Same as Vim itself (see :h license)
+
+if exists('b:current_syntax')
+    finish
+endif
+
+let s:cpo_save = &cpoptions
+set cpoptions&vim
+
+" Comments start with # or //
+syntax region CMakeCacheComment start="#\|//" end="$"
+
+" Match 'key' in key:type=value
+syntax match CMakeCacheKey "^\s*\w\+\(-ADVANCED\)\=:"me=e-1
+
+" Highlight 'str' in key:STRING=str (many thanks to Nickspoons in #vim!)
+syntax region CMakeCacheStringVar   matchgroup=CMakeCacheType start=":STRING="ms=s+1,rs=e-1 end="$" contains=CMakeCacheString keepend
+syntax region CMakeCacheString      start="="ms=s+1 end="$" contained
+
+" Highlight boolean 'value' in key:BOOL=value
+syntax region CMakeCacheBoolVar     matchgroup=CMakeCacheType start=":BOOL="ms=s+1,rs=e-1 end="$" contains=CMakeCacheBool keepend
+syntax region CMakeCacheBool        start="="ms=s+1 end="$" contained
+
+" Highlight 'path' in key:PATH=path
+syntax region CMakeCachePathVar     matchgroup=CMakeCacheType start=":PATH="ms=s+1,rs=e-1 end="$" contains=CMakeCachePath keepend
+syntax region CMakeCachePath        start="="ms=s+1 end="$" contained
+
+" Highlight 'file' in key:FILEPATH=file
+syntax region CMakeCacheFilePathVar matchgroup=CMakeCacheType start=":FILEPATH="ms=s+1,rs=e-1 end="$" contains=CMakeCacheFilePath keepend
+syntax region CMakeCacheFilePath    start="="ms=s+1 end="$" contained
+
+" Highlight 'value' in key:STATIC=value
+syntax region CMakeCacheStaticVar   matchgroup=CMakeCacheType start=":STATIC="ms=s+1,rs=e-1 end="$" contains=CMakeCacheStatic keepend
+syntax region CMakeCacheStatic      start="="ms=s+1 end="$" contained
+
+" Highlight 'value' in key:Internal=value
+syntax region CMakeCacheInternalVar matchgroup=CMakeCacheType start=":INTERNAL="ms=s+1,rs=e-1 end="$" contains=CMakeCacheInternal keepend
+syntax region CMakeCacheInternal    start="="ms=s+1 end="$" contained
+
+hi def link CMakeCacheComment   Comment
+hi def link CMakeCacheKey       Identifier
+hi def link CMakeCacheString    String
+hi def link CMakeCacheBool      Constant
+hi def link CMakeCachePath      Directory
+hi def link CMakeCacheFilePath  Normal
+hi def link CMakeCacheStatic    Normal
+hi def link CMakeCacheInternal  Normal
+
+" Highlight 'type' in key:type=value
+hi def link CMakeCacheType      Type
+
+let b:current_syntax = 'cmakecache'
+
+let &cpoptions = s:cpo_save
+unlet s:cpo_save