X64: Implement DoComputeOsrOutputFrame and fix Generate_OnStackReplacement.

X64: Implement DoComputeOsrOutputFrame and fix Generate_OnStackReplacement.

The existing version does not have a correct implementation of
Generate_OnStackReplacement since we do not correctly find the loop
depth. This is mainly because EmitStackCheck in full-codegen-x64.cc
did not write it and partly due to us reading at the wrong offset
(which had no effect when it was not written in the first place, we
simply got a random number from the next instruction).

The DoComputeOsrOoutputFrame is very similar to the ia32 version.

Review URL: http://codereview.chromium.org/6581028

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6931 ce2b1a6d-e550-0410-aec6-3dcde31c8c00