Context specialization enables inlining (at least currently it is the
only enabler for inlining), but inlining enables more possibilities for
context specialization. So we really need to run them together.

This is especially important with the "module based builtins" that we're
working towards.

BUG=v8:3952
LOG=n

Review URL: https://codereview.chromium.org/988423004

Cr-Commit-Position: refs/heads/master@{#27085}