[regexp] Migrate constructor and compile to CSA

src/runtime/runtime-regexp.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/conversions-inl.h"
 #include "src/isolate-inl.h"
 #include "src/messages.h"
@@ skipping 1647 matching lines @@
 }
 
 RUNTIME_FUNCTION(Runtime_RegExpExecReThrow) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 4);
   Object* exception = isolate->pending_exception();
   isolate->clear_pending_exception();
   return isolate->ReThrow(exception);
 }
 
+RUNTIME_FUNCTION(Runtime_RegExpInitializeAndCompile) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 3);
+  CONVERT_ARG_HANDLE_CHECKED(JSRegExp, regexp, 0);
+  CONVERT_ARG_HANDLE_CHECKED(String, source, 1);
+  CONVERT_ARG_HANDLE_CHECKED(String, flags, 2);
+
+  RETURN_FAILURE_ON_EXCEPTION(isolate,
+                              JSRegExp::Initialize(regexp, source, flags));
+
+  return *regexp;
+}
 
 RUNTIME_FUNCTION(Runtime_IsRegExp) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);
   CONVERT_ARG_CHECKED(Object, obj, 0);
   return isolate->heap()->ToBoolean(obj->IsJSRegExp());
 }
 
 }  // namespace internal
 }  // namespace v8