Fix perf jitdump integration.

When emitting JIT_CODE_LOAD for Crankshafted code exclude Safepoint Table from the size of the code.

This cleans up perf annotate output - because otherwise it confusingly tries to disassemble safepoint table.

R=jarin@chromium.org
BUG=

Review URL: https://codereview.chromium.org/556453008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23814 ce2b1a6d-e550-0410-aec6-3dcde31c8c00