Remove the following runtime functions, which are not used throughout
the code base anymore:

  - %GetWeakMapEntries
  - %GetWeakSetValues
  - %MapIteratorClone
  - %SetIteratorClone
  - %StringNotEqual
  - %FunctionGetName
  - %IsConstructor
  - %SetCode

Bug: v8:8015
Change-Id: Iaf441d58e9b9bc77ef5bf93cb82ada87fb1ff5a7
Reviewed-on: https://chromium-review.googlesource.com/1238574
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56136}