Tiny refactoring - change compilation phase parameter for CopyForInlining from a boolean to an enum.

BUG=
TEST=

Review URL: http://codereview.chromium.org/6913021

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7782 ce2b1a6d-e550-0410-aec6-3dcde31c8c00