[regexp] Abort on compilation overflow if flag passed

Abort execution on stack overflow during compilation if
--abort-on-stack-or-string-length-overflow was passed (for correctness
fuzzer support).

Bug: chromium:778962
Change-Id: Idd50b47c4ddc03b7839ce850da95502fce4cc848
Reviewed-on: https://chromium-review.googlesource.com/750842Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49079}

src/regexp/jsregexp.cc

@@ -330,6 +330,10 @@ bool RegExpImpl::CompileIrregexp(Handle<JSRegExp> re,
                             sample_subject, is_one_byte);
   if (result.error_message != nullptr) {
     // Unable to compile regexp.
+    if (FLAG_abort_on_stack_or_string_length_overflow &&
+        strncmp(result.error_message, "Stack overflow", 15) == 0) {
+      FATAL("Aborting on stack overflow");
+    }
     Handle<String> error_message = isolate->factory()->NewStringFromUtf8(
         CStrVector(result.error_message)).ToHandleChecked();
     ThrowRegExpException(re, error_message);