Cherry pick 588e15c and c0d4bb8 from upstream V8

Checklist

• make -j4 test (UNIX), or vcbuild test nosign (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

Affected core subsystem(s)

deps

Description of change

Backport of bugfix from upstream V8. This is already fixed in versions 5.2 and 5.3 of V8 but is needed for 5.1.

cc @nodejs/v8