Add deopt fuzzer tool.

Can be run as a stand-alone script like run-tests.

Executes first all tests of a given test suite to collect the maximum number of possible deopt points. Runs then a fuzzing phase with artificial deoptimizations triggered during testing.

Works for now with mjsunit and ia32 only.

R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/19931005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15855 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Restore test and behavior prior to deferred stack trace formatting.

R=mstarzinger@chromium.org
TEST=stack-traces-overflow.js

Review URL: https://codereview.chromium.org/19805003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15856 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
More Math.abs tweaks for Intel platforms.

Made ia32/x64 code more uniform. Minor jump tweaks.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/20067003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15857 ce2b1a6d-e550-0410-aec6-3dcde31c8c00