Handle exceptions thrown while parsing lazy functions for inlining.

Handle exceptions thrown while parsing lazy functions for inlining.
We currently leave the exception as pending without returning a Failure::Exception() value. This is either caught immediately if running with --debug-code, or caught later by an assert in debug mode.

This change makes the pending exception be cleared before returning from the failed optimization attempt.

BUG=v8::1145
TEST=test/mjsunit/regress/regress-1145.js

Review URL: http://codereview.chromium.org/6524039

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6832 ce2b1a6d-e550-0410-aec6-3dcde31c8c00