In reporting step-in positions be more accurate with a position the debugger paused at

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/23264015

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16472 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Cleanup Semaphore class.

Drop the previous Semaphore class from platform files.

Add new Semaphore class using the new TimeDelta class for
the WaitFor() operation. Consistently assert correct behaviour
for the different implementations.

Improve test coverage of the Semaphore class.

R=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/23748003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16473 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Fix Mac llvm-gcc42 build after commit r16473.

TBR=machenbach@chromium.org

Review URL: https://codereview.chromium.org/23437020

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@16474 ce2b1a6d-e550-0410-aec6-3dcde31c8c00