No longer OOM on invalid string length.

src/heap-inl.h

Index: src/heap-inl.h
diff --git a/src/heap-inl.h b/src/heap-inl.h
index 7e465d5c9386858c05088c89073d3365c232167e..063cf30ff3cd178b4c7efda22fcc2447252e90c8 100644
--- a/src/heap-inl.h
+++ b/src/heap-inl.h
@@ -138,7 +138,7 @@ MaybeObject* Heap::AllocateInternalizedStringImpl(
 MaybeObject* Heap::AllocateOneByteInternalizedString(Vector<const uint8_t> str,
                                                      uint32_t hash_field) {
   if (str.length() > String::kMaxLength) {
-    v8::internal::Heap::FatalProcessOutOfMemory("invalid string length", true);
+    return isolate()->ThrowInvalidStringLength();
   }
   // Compute map and object size.
   Map* map = ascii_internalized_string_map();
@@ -171,7 +171,7 @@ MaybeObject* Heap::AllocateOneByteInternalizedString(Vector<const uint8_t> str,
 MaybeObject* Heap::AllocateTwoByteInternalizedString(Vector<const uc16> str,
                                                      uint32_t hash_field) {
   if (str.length() > String::kMaxLength) {
-    v8::internal::Heap::FatalProcessOutOfMemory("invalid string length", true);
+    return isolate()->ThrowInvalidStringLength();
   }
   // Compute map and object size.
   Map* map = internalized_string_map();