Bug 1415161 - Get rid of slow JSContext::findVersion calls when parsing regular expressions. r=anba

js/src/builtin/RegExp.cpp

@@ -178,7 +178,7 @@ js::ExecuteRegExpLegacy(JSContext* cx, RegExpStatics* res, Handle<RegExpObject*>
 static bool
 CheckPatternSyntax(JSContext* cx, HandleAtom pattern, RegExpFlag flags)
 {
-    CompileOptions options(cx);
+    CompileOptions options(cx, JSVERSION_DEFAULT);
     frontend::TokenStream dummyTokenStream(cx, options, nullptr, 0, nullptr);
     return irregexp::ParsePatternSyntax(dummyTokenStream, cx->tempLifoAlloc(), pattern,
                                         flags & UnicodeFlag);

js/src/vm/RegExpObject.cpp

@@ -242,7 +242,7 @@ RegExpObject::create(JSContext* cx, HandleAtom source, RegExpFlag flags,
 {
     Maybe<CompileOptions> dummyOptions;
     if (!tokenStream && !options) {
-        dummyOptions.emplace(cx);
+        dummyOptions.emplace(cx, JSVERSION_DEFAULT);
         options = dummyOptions.ptr();
     }
     Maybe<TokenStream> dummyTokenStream;
@@ -987,7 +987,7 @@ RegExpShared::compile(JSContext* cx, MutableHandleRegExpShared re, HandleAtom pa
     if (!re->ignoreCase() && !StringHasRegExpMetaChars(pattern))
         re->canStringMatch = true;
 
-    CompileOptions options(cx);
+    CompileOptions options(cx, JSVERSION_DEFAULT);
     frontend::TokenStream dummyTokenStream(cx, options, nullptr, 0, nullptr);
 
     LifoAllocScope scope(&cx->tempLifoAlloc());