Using runtime over syntax include

syntax include has a sort of sugar to it that forces all sourced
highlighting to be contained, this will break certain more general
highlighting for jsFlow.

runtime on the other hand, works exactly as you'd expect.

Author: amadeus

syntax/javascript.vim

@@ -193,15 +193,15 @@ syntax region  jsEnvComment     start="\%^#!" end="$" display
 syntax region  jsCvsTag         contained start="\$\cid:" end="\$" oneline
 
 if !exists("javascript_ignore_javaScriptdoc")
-  syntax include extras/jsdocs.vim
+  runtime extras/jsdocs.vim
 endif
 
 if exists("javascript_plugin_flow")
-  syntax include extras/flow.vim
+  runtime extras/flow.vim
 endif
 
 if exists("javascript_plugin_ngdocs")
-  syntax include extras/ngdocs.vim
+  runtime extras/ngdocs.vim
 endif
 
 syntax cluster jsExpression  contains=jsBracket,jsParen,jsObject,jsBlock,jsTernaryIf,jsTaggedTemplate,jsTemplateString,jsString,jsRegexpString,jsNumber,jsFloat,jsOperator,jsBooleanTrue,jsBooleanFalse,jsNull,jsFunction,jsArrowFunction,jsGlobalObjects,jsExceptions,jsFutureKeys,jsDomErrNo,jsDomNodeConsts,jsHtmlEvents,jsFuncCall,jsUndefined,jsNan,jsPrototype,jsBuiltins,jsNoise,jsClassDefinition,jsArrowFunction,jsArrowFuncArgs,jsParensError,jsComment,jsArguments,jsThis,jsSuper