Fix bogus assertions for tracing and verify.

R=mstarzinger@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/15778012

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14985 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Do not GC prior to every parallel recompile.

R=jkummerow@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/16410005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14986 ce2b1a6d-e550-0410-aec6-3dcde31c8c00