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.




Committed: http://code.google.com/p/v8/source/detail?r=6931

[Rico, 2011-02-24 08:01:49]

Adding Florian as reviewer since Kevin is on vacation.

[Rico, 2011-02-24 11:36:18]

Uploaded new version using testl instead of testq in EmitStackCheck (since this
value will never be greater than 6 it will always fit in a uint8)

[fschneider, 2011-02-24 11:45:35]

LGTM.