Port and integrate the irregexp engine from V8

runtime/vm/regexp_parser.cc

Index: runtime/vm/regexp_parser.cc
diff --git a/runtime/vm/regexp_parser.cc b/runtime/vm/regexp_parser.cc
index 003e554646dd683854d696ad1e061eb00510d10b..a0f114b49f54049d1cce5a9065a2f3831b27250f 100644
--- a/runtime/vm/regexp_parser.cc
+++ b/runtime/vm/regexp_parser.cc
@@ -267,10 +267,15 @@ bool RegExpParser::ParseRegExp(const String& input,
     result->capture_count = capture_count;
   } else {
     ASSERT(!result->error.IsNull());
-
-    // TODO(jgruber): Throw a format exception once we are ready to replace
-    // jscre. For now, we ignore the error set by LongJump.
     Isolate::Current()->object_store()->clear_sticky_error();
+
+    // Throw a FormatException on parsing failures.
+    const String& message = String::Handle(
+          String::Concat(result->error, input));
+    const Array& args = Array::Handle(Array::New(1));
+    args.SetAt(0, message);
+
+    Exceptions::ThrowByType(Exceptions::kFormat, args);
   }
   return !parser.failed();
 }