runtime(vim): Update base-syntax, remove unused vimString region

These were included with the initial release of the syntax file for Vim
5 and were probably intended to allow for syn-region start/skip/end
patterns with a '!' or '+' delimiter.  However, these cases are
currently handled by the vimSynRegPat group.

The removed patterns never match anywhere in the distributed runtime
files and it is believed that this is generally true.

closes: #14035

Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/generator/vim.vim.base b/runtime/syntax/generator/vim.vim.base
index 37bc03a..cf4aedd 100644
--- a/runtime/syntax/generator/vim.vim.base
+++ b/runtime/syntax/generator/vim.vim.base
@@ -333,8 +333,6 @@
 syn cluster	vimStringGroup	contains=vimEscape,vimEscapeBrace,vimPatSep,vimNotPatSep,vimPatSepErr,vimPatSepZone,@Spell
 syn region	vimString	oneline keepend	start=+[^a-zA-Z>!\\@]"+lc=1 skip=+\\\\\|\\"+ matchgroup=vimStringEnd end=+"+	contains=@vimStringGroup
 syn region	vimString	oneline keepend	start=+[^a-zA-Z>!\\@]'+lc=1 end=+'+
-syn region	vimString	oneline	start=+=!+lc=1	skip=+\\\\\|\\!+ end=+!+	contains=@vimStringGroup
-syn region	vimString	oneline	start="=+"lc=1	skip="\\\\\|\\+" end="+"	contains=@vimStringGroup
 "syn region	vimString	oneline	start="\s/\s*\A"lc=1 skip="\\\\\|\\+" end="/"	contains=@vimStringGroup  " see tst45.vim
 syn match	vimString	contained	+"[^"]*\\$+	skipnl nextgroup=vimStringCont
 syn match	vimStringCont	contained	+\(\\\\\|.\)\{-}[^\\]"+
diff --git a/runtime/syntax/vim.vim b/runtime/syntax/vim.vim
index a69dedc..33cb7cc 100644
--- a/runtime/syntax/vim.vim
+++ b/runtime/syntax/vim.vim
@@ -376,8 +376,6 @@
 syn cluster	vimStringGroup	contains=vimEscape,vimEscapeBrace,vimPatSep,vimNotPatSep,vimPatSepErr,vimPatSepZone,@Spell
 syn region	vimString	oneline keepend	start=+[^a-zA-Z>!\\@]"+lc=1 skip=+\\\\\|\\"+ matchgroup=vimStringEnd end=+"+	contains=@vimStringGroup
 syn region	vimString	oneline keepend	start=+[^a-zA-Z>!\\@]'+lc=1 end=+'+
-syn region	vimString	oneline	start=+=!+lc=1	skip=+\\\\\|\\!+ end=+!+	contains=@vimStringGroup
-syn region	vimString	oneline	start="=+"lc=1	skip="\\\\\|\\+" end="+"	contains=@vimStringGroup
 "syn region	vimString	oneline	start="\s/\s*\A"lc=1 skip="\\\\\|\\+" end="/"	contains=@vimStringGroup  " see tst45.vim
 syn match	vimString	contained	+"[^"]*\\$+	skipnl nextgroup=vimStringCont
 syn match	vimStringCont	contained	+\(\\\\\|.\)\{-}[^\\]"+