The current method of marking functions for optimization, which replaces
the JSFunction's code object with one that triggers optimization, would
never allow unnamed functions to be optimized. This is an issue for a
style of programming which heavily relies on passing around closures.

This patch sets a bit on the SharedFunctionInfo when a JSFunction is
marked. When another JSFunction referring to the same SharedFunctionInfo
is lazily compiled, it immediately triggers a non-concurrent optimize.

BUG=v8:5512

Review-Url: https://chromiumcodereview.appspot.com/2437043002
Cr-Commit-Position: refs/heads/master@{#40506}