This switches our inlining tests (i.e. cctest/test-run-inlining) to rely
on global object instead of function context specialization, which is
more in sync with what we are actually shipping. It will also allow us
to test inlining with the BytecodeGraphBuilder without having to add
support for function context specialization just for testing purposes.

R=bmeurer@chromium.org
TEST=cctest/test-run-inlining
BUG=v8:5251

Review-Url: https://codereview.chromium.org/2200673002
Cr-Commit-Position: refs/heads/master@{#38209}