Throw when case mapping result > max string length

src/runtime/runtime-i18n.cc

Index: src/runtime/runtime-i18n.cc
diff --git a/src/runtime/runtime-i18n.cc b/src/runtime/runtime-i18n.cc
index 7d2594cd327fa6db1246110a17083ef7096160c3..fb6fbe76070ac667d73b72ee75e515fe9913e1f1 100644
--- a/src/runtime/runtime-i18n.cc
+++ b/src/runtime/runtime-i18n.cc
@@ -859,8 +859,10 @@ MUST_USE_RESULT Object* LocaleConvertCase(Handle<String> s, Isolate* isolate,
   // This is not a real loop. It'll be executed only once (no overflow) or
   // twice (overflow).
   for (int i = 0; i < 2; ++i) {
-    result =
-        isolate->factory()->NewRawTwoByteString(dest_length).ToHandleChecked();
+    // Case conversion can increase the string length (e.g. sharp-S => SS) so
+    // that we have to handle RangeError exceptions here.
+    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
+        isolate, result, isolate->factory()->NewRawTwoByteString(dest_length));
     DisallowHeapAllocation no_gc;
     String::FlatContent flat = s->GetFlatContent();
     const UChar* src = GetUCharBufferFromFlat(flat, &sap, src_length);