Support class static initialization blocks

[tuberry]

Class static initialization blocks break highlighting:

Example from MDN:

class ClassWithStaticInitializationBlock {
  static staticProperty1 = 'Property 1';
  static staticProperty2;
  static {
    this.staticProperty2 = 'Property 2';
  }
}

Thanks in advance!

[tuberry]

A solution:

diff --git a/syntax/javascript.vim b/syntax/javascript.vim
diff --git a/syntax/javascript.vim b/syntax/javascript.vim
index a30956eb..4ea091d7 100644
--- a/syntax/javascript.vim
+++ b/syntax/javascript.vim
@@ -145,7 +145,7 @@ syntax region  jsParenRepeat        contained matchgroup=jsParensRepeat        s
 syntax region  jsParenSwitch        contained matchgroup=jsParensSwitch        start=/(/  end=/)/  contains=@jsAll skipwhite skipempty nextgroup=jsSwitchBlock extend fold
 syntax region  jsParenCatch         contained matchgroup=jsParensCatch         start=/(/  end=/)/  skipwhite skipempty nextgroup=jsTryCatchBlock extend fold
 syntax region  jsFuncArgs           contained matchgroup=jsFuncParens          start=/(/  end=/)/  contains=jsFuncArgCommas,jsComment,jsFuncArgExpression,jsDestructuringBlock,jsDestructuringArray,jsRestExpression,jsFlowArgumentDef skipwhite skipempty nextgroup=jsCommentFunction,jsFuncBlock,jsFlowReturn extend fold
-syntax region  jsClassBlock         contained matchgroup=jsClassBraces         start=/{/  end=/}/  contains=jsClassFuncName,jsClassMethodType,jsArrowFunction,jsArrowFuncArgs,jsComment,jsGenerator,jsDecorator,jsClassProperty,jsClassPropertyComputed,jsClassStringKey,jsAsyncKeyword,jsNoise extend fold
+syntax region  jsClassBlock         contained matchgroup=jsClassBraces         start=/{/  end=/}/  contains=jsClassStaticBlock,jsClassFuncName,jsClassMethodType,jsArrowFunction,jsArrowFuncArgs,jsComment,jsGenerator,jsDecorator,jsClassProperty,jsClassPropertyComputed,jsClassStringKey,jsAsyncKeyword,jsNoise extend fold
 syntax region  jsFuncBlock          contained matchgroup=jsFuncBraces          start=/{/  end=/}/  contains=@jsAll,jsBlock extend fold
 syntax region  jsIfElseBlock        contained matchgroup=jsIfElseBraces        start=/{/  end=/}/  contains=@jsAll,jsBlock extend fold
 syntax region  jsTryCatchBlock      contained matchgroup=jsTryCatchBraces      start=/{/  end=/}/  contains=@jsAll,jsBlock skipwhite skipempty nextgroup=jsCatch,jsFinally extend fold
@@ -186,6 +186,7 @@ syntax keyword jsClassKeyword           contained class
 syntax keyword jsExtendsKeyword         contained extends skipwhite skipempty nextgroup=@jsExpression
 syntax match   jsClassNoise             contained /\./
 syntax match   jsClassFuncName          contained /\<\K\k*\ze\s*[(<]/ skipwhite skipempty nextgroup=jsFuncArgs,jsFlowClassFunctionGroup
+syntax match   jsClassStaticBlock       contained /\<static\>/ skipwhite skipempty nextgroup=jsBlock
 syntax match   jsClassMethodType        contained /\<\%([gs]et\|static\)\ze\s\+\K\k*/ skipwhite skipempty nextgroup=jsAsyncKeyword,jsClassFuncName,jsClassProperty
 syntax region  jsClassDefinition                  start=/\<class\>/ end=/\(\<extends\>\s\+\)\@<!{\@=/ contains=jsClassKeyword,jsExtendsKeyword,jsClassNoise,@jsExpression,jsFlowClassGroup skipwhite skipempty nextgroup=jsCommentClass,jsClassBlock,jsFlowClassGroup
 syntax match   jsClassProperty          contained /\<\K\k*\ze\s*[=;]/ skipwhite skipempty nextgroup=jsClassValue,jsFlowClassDef
@@ -355,6 +356,7 @@ if version >= 508 || !exists("did_javascript_syn_inits")
   HiLink jsRestExpression       jsFuncArgs
   HiLink jsSwitchColon          Noise
   HiLink jsClassMethodType      Type
+  HiLink jsClassStaticBlock     Type
   HiLink jsObjectMethodType     Type
   HiLink jsClassDefinition      jsFuncName
   HiLink jsBlockLabel           Identifier