The GlobalEval JavaScript function was just a small driver for stuff
implemented in C++ anyway, so there's no point in having it around at
all. The next step will be to move the Function constructor to C++ as
well, which is the other user of %CompileString.

R=yangguo@chromium.org
BUG=chromium:535408
LOG=n

Review URL: https://codereview.chromium.org/1540893004

Cr-Commit-Position: refs/heads/master@{#33006}