Fix: Syntax highlighting for various issues (#2810)

* highlighter: Fix region & pattern detection

* syntax/sh: Highlight upper case options too

* syntax/c(pp): Try to synchronize the rules to lower the maintenance effort

* syntax/ruby: Fix explicit filename detection in directories

* highlighter: Respect skip rules in regions

* syntax/sh: Fix parameter expansion, cond. flags and generalize filename via ""

* syntax/php|vi: Correct strings in comments to comments only

Additionally improve vimscript comment handling.

* highlighter: Remove problematic start|end check in find(all)Index()

...and additionally remove recursive region end detection

runtime/syntax/cpp.yaml

@@ -9,7 +9,7 @@ rules:
     - type: "\\b(((s?size)|((u_?)?int(8|16|32|64|ptr))|char(8|16|32))_t|wchar_t)\\b"
     - type: "\\b[a-z_][0-9a-z_]+(_t|_T)\\b"
     - type: "\\b(final|override)\\b"
-    - type.keyword: "\\b(auto|volatile|const(expr|eval|init)?|mutable|register|thread_local|static|extern|decltype|explicit|virtual)\\b"
+    - statement: "\\b(auto|volatile|const(expr|eval|init)?|mutable|register|thread_local|static|extern|decltype|explicit|virtual)\\b"
     - statement: "\\b(class|namespace|template|typename|this|friend|using|public|protected|private|noexcept)\\b"
     - statement: "\\b(concept|requires)\\b"
     - statement: "\\b(import|export|module)\\b"
@@ -34,7 +34,7 @@ rules:
     - constant.number: "(\\b(([0-9']*[.][0-9']+|[0-9']+[.][0-9']*)([Ee][+-]?[0-9']+)?|[0-9']+[Ee][+-]?[0-9']+)[FfLl]?\\b)"
       # Hexadecimal Floating-point Literals
     - constant.number: "(\\b0[Xx]([0-9a-zA-Z']*[.][0-9a-zA-Z']+|[0-9a-zA-Z']+[.][0-9a-zA-Z']*)[Pp][+-]?[0-9']+[FfLl]?\\b)"
-    - constant.bool: "(\\b(true|false|NULL|nullptr)\\b)"
+    - constant.bool: "(\\b(true|false|NULL|nullptr|TRUE|FALSE)\\b)"
 
     - constant.string:
         start: "\""