Use optparse in js2c.py for python compatibility
Use optparse in js2c.py for python compatibility

Without this change, V8 won't build on RHEL/CentOS 6 because the distro
python is too old to know about the argparse module.

Can this commit be cherry-picked to the 4.4 branch?  It should apply
cleanly.

BUG=

Review URL: https://codereview.chromium.org/1192973004

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#29186}

UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh,UniversalFuture/moosh