X64: Fixed conversion between tread_id (int) and void*.

X64: Fixed conversion between tread_id (int) and void*.
Thread id's are always int size values (generated from an int counter).

[Lasse Reichstein, 2009-05-06 12:28:37]

Thread id's are always int. Fixed conversion to and from void*.
Review please.

[Dean McNamee, 2009-05-06 12:54:39]

http://codereview.chromium.org/113030/diff/1/2
File src/v8threads.cc (right):

http://codereview.chromium.org/113030/diff/1/2#newcode312
Line 312: void* stored_thread_id = Thread::GetThreadLocal(thread_id_key);
I would add to platform.h a GetThreadLocalInt, and do the cast there.

http://codereview.chromium.org/113030/diff/1/2#newcode313
Line 313: intptr_t thread_id_number = bit_cast<intptr_t,
void*>(stored_thread_id);
this is actually an incorrect use of bit_cast.

http://codereview.chromium.org/113030/diff/1/2#newcode322
Line 322: Thread::SetThreadLocal(thread_id_key, bit_cast<void*,
intptr_t>(new_id));
SetThreadLocalInt