port 546dd77f

Original Commit Message:
  Since some builtins use StringToNumberStub (so the code is always there),
  it makes more sense to have StringToNumber builtin.

R=jarin@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com, mbrandy@us.ibm.com, bjaideep@ca.ibm.com
BUG=

Review-Url: https://codereview.chromium.org/2052833003
Cr-Commit-Position: refs/heads/master@{#36872}