Do not modify FLAG_parallel_recompilation after start up.

R=jkummerow@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/17202006

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15195 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Tweak type info threshold.

R=jkummerow@chromium.org
BUG=

Review URL: https://chromiumcodereview.appspot.com/17390004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15196 ce2b1a6d-e550-0410-aec6-3dcde31c8c00