Fix kStoreBufferBlockProcessRuntimeEntry call sequence.

Fix kStoreBufferBlockProcessRuntimeEntry calling sequence.

Poping of volatile registers was performed without taking into account the fact that stack pointer could have been  modified to ensure correct alignment _after_ volatile registers were pushed. 

Enable --use-ssa on x64 again. 

BUG=4221
Committed: https://code.google.com/p/dart/source/detail?r=10007

[Vyacheslav Egorov (Google), 2012-07-27 17:52:26]

Please take a look.

[Vyacheslav Egorov (Google), 2012-07-27 18:46:30]

Amended my patch.

Actually our runtime functions are following C calling convention (caller cleans
up the stack), so we need to restore stack pointer before restoring saved
registers with pop even if platform has no alignment requirements because we
need to drop space reserved for arguments.

[siva, 2012-07-27 20:41:21]

lgtm

https://chromiumcodereview.appspot.com/10820053/diff/2002/runtime/vm/assemble...
File runtime/vm/assembler_ia32.cc (right):

https://chromiumcodereview.appspot.com/10820053/diff/2002/runtime/vm/assemble...
runtime/vm/assembler_ia32.cc:1531: // Preserve volatile registers.
ASSERT(kNumberOfVolatileRegisters == 3);
or better still generate some assembly code similar to CHECK_STACK_ALIGNMENT
which would in debug mode ensure that EBP - ESP is (kNumberOfVolatileRegisters *
kWordSize);

https://chromiumcodereview.appspot.com/10820053/diff/2002/runtime/vm/assemble...
runtime/vm/assembler_ia32.cc:1544: const intptr_t kNumberOfVolatileRegisters =
3;
Pull this to the class so that it is accessible from EnterCallRuntimeFrame also.

https://chromiumcodereview.appspot.com/10820053/diff/2002/runtime/vm/assemble...
runtime/vm/assembler_ia32.cc:1547: // Restore volatile registers.
ASSERT(kNumberofVolatileRegisters == 3);

https://chromiumcodereview.appspot.com/10820053/diff/2002/runtime/vm/assemble...
File runtime/vm/assembler_x64.cc (right):

https://chromiumcodereview.appspot.com/10820053/diff/2002/runtime/vm/assemble...
runtime/vm/assembler_x64.cc:1679: // Preserve volatile registers.
ASSERT(kNumberOfVolatileRegisters == 9);

https://chromiumcodereview.appspot.com/10820053/diff/2002/runtime/vm/assemble...
runtime/vm/assembler_x64.cc:1700: const intptr_t kNumberOfVolatileRegisters = 9;
ditto comment regarding kNumberOfVolatileRegisters.

https://chromiumcodereview.appspot.com/10820053/diff/2002/runtime/vm/assemble...
runtime/vm/assembler_x64.cc:1713: popq(RAX);
ditto comment regarding kNumberOfVolatileRegisters

[Vyacheslav Egorov (Google), 2012-07-30 10:36:38]

Thanks for the review. I addressed your comments in a slightly different
fashion: by declaring an array of registers to save restore (to guarantee that
we restore registers in the correct order as well). 

Landing.