runtime(tex): add texEmphStyle to texMatchGroup in syntax script

fixes: #16228

Co-authored-by: Github User JordL
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/syntax/tex.vim b/runtime/syntax/tex.vim
index 77a40e1..4f35bba 100644
--- a/runtime/syntax/tex.vim
+++ b/runtime/syntax/tex.vim
@@ -3,7 +3,8 @@
 " Maintainer:	This runtime file is looking for a new maintainer.
 " Former Maintainer: Charles E. Campbell
 " Last Change:	Apr 22, 2022
-"   2024 Feb 19 by Vim Project (announce adoption)
+"   2024 Feb 19 by Vim Project: announce adoption
+"   2025 Jan 18 by Vim Project: add texEmphStyle to texMatchGroup, #16228
 " Version:	121
 " Former URL:	http://www.drchip.org/astronaut/vim/index.html#SYNTAX_TEX
 "
@@ -176,11 +177,11 @@
 endif
 if !s:tex_nospell
  if !s:tex_no_error
-  syn cluster texMatchGroup		contains=texAccent,texBadMath,texComment,texDefCmd,texDelimiter,texDocType,texError,texInput,texLength,texLigature,texMatcher,texNewCmd,texNewEnv,texOnlyMath,texParen,texRefZone,texSection,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle,texBoldStyle,texBoldItalStyle,texItalStyle,texItalBoldStyle,texZone,texInputFile,texOption,@Spell
+  syn cluster texMatchGroup		contains=texAccent,texBadMath,texComment,texDefCmd,texDelimiter,texDocType,texError,texInput,texLength,texLigature,texMatcher,texNewCmd,texNewEnv,texOnlyMath,texParen,texRefZone,texSection,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle,texBoldStyle,texBoldItalStyle,texItalStyle,texItalBoldStyle,texEmphStyle,texZone,texInputFile,texOption,@Spell
   syn cluster texMatchNMGroup		contains=texAccent,texBadMath,texComment,texDefCmd,texDelimiter,texDocType,texError,texInput,texLength,texLigature,texMatcherNM,texNewCmd,texNewEnv,texOnlyMath,texParen,texRefZone,texSection,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle,texBoldStyle,texBoldItalStyle,texItalStyle,texItalBoldStyle,texZone,texInputFile,texOption,@Spell
   syn cluster texStyleGroup		contains=texAccent,texBadMath,texComment,texDefCmd,texDelimiter,texDocType,texError,texInput,texLength,texLigature,texNewCmd,texNewEnv,texOnlyMath,texParen,texRefZone,texSection,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle,texBoldStyle,texBoldItalStyle,texItalStyle,texItalBoldStyle,texZone,texInputFile,texOption,texStyleStatement,texStyleMatcher,@Spell
  else
-  syn cluster texMatchGroup		contains=texAccent,texBadMath,texComment,texDefCmd,texDelimiter,texDocType,texInput,texLength,texLigature,texMatcher,texNewCmd,texNewEnv,texOnlyMath,texParen,texRefZone,texSection,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle,texBoldStyle,texBoldItalStyle,texItalStyle,texItalBoldStyle,texZone,texInputFile,texOption,@Spell
+  syn cluster texMatchGroup		contains=texAccent,texBadMath,texComment,texDefCmd,texDelimiter,texDocType,texInput,texLength,texLigature,texMatcher,texNewCmd,texNewEnv,texOnlyMath,texParen,texRefZone,texSection,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle,texBoldStyle,texBoldItalStyle,texItalStyle,texItalBoldStyle,texEmphStyle,texZone,texInputFile,texOption,@Spell
   syn cluster texMatchNMGroup		contains=texAccent,texBadMath,texComment,texDefCmd,texDelimiter,texDocType,texInput,texLength,texLigature,texMatcherNM,texNewCmd,texNewEnv,texOnlyMath,texParen,texRefZone,texSection,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle,texBoldStyle,texBoldItalStyle,texItalStyle,texItalBoldStyle,texZone,texInputFile,texOption,@Spell
   syn cluster texStyleGroup		contains=texAccent,texBadMath,texComment,texDefCmd,texDelimiter,texDocType,texInput,texLength,texLigature,texNewCmd,texNewEnv,texOnlyMath,texParen,texRefZone,texSection,texSpecialChar,texStatement,texString,texTypeSize,texTypeStyle,texBoldStyle,texBoldItalStyle,texItalStyle,texItalBoldStyle,texZone,texInputFile,texOption,texStyleStatement,texStyleMatcher,@Spell
  endif