Backport @10366 to 3.6

backport @10366, @10367 and @10402 to 3.6

Add seed to hash of numeric keyed properties.

Minor cleanups of numeric seeded hashing patch.

Split NumberDictionary into a randomly seeded and an unseeded version.
We don't want to randomize the stub cache.

R=erik.corry@gmail.com

[Erik Corry, 2012-01-11 10:20:35]

LGTM with two nits.

http://codereview.chromium.org/9190001/diff/4007/src/ia32/macro-assembler-ia3...
File src/ia32/macro-assembler-ia32.cc (right):

http://codereview.chromium.org/9190001/diff/4007/src/ia32/macro-assembler-ia3...
src/ia32/macro-assembler-ia32.cc:764: mov(scratch,
Immediate(Heap::kHashSeedRootIndex));
There's a missing SmiUntag here.  Probably it doesn't matter because there are
no number dictionaries in the snapshot, but we should fix it anyway.

I will fix it on bleeding edge.

http://codereview.chromium.org/9190001/diff/4007/src/ia32/macro-assembler-ia3...
src/ia32/macro-assembler-ia32.cc:766: times_pointer_size,
Somehow the indentation got borked here.

[isaacs, 2012-01-13 17:06:30]

What's the status of this?

Erik, are you waiting for Fedor to fix the nits and update?

I'm eager to release node 0.6.8 with this fix as soon as possible.

[Erik Corry, 2012-01-19 15:35:00]

LGTM and committed.

http://codereview.chromium.org/9190001/diff/9001/src/arm/macro-assembler-arm.cc
File src/arm/macro-assembler-arm.cc (right):

http://codereview.chromium.org/9190001/diff/9001/src/arm/macro-assembler-arm....
src/arm/macro-assembler-arm.cc:1362: mul(t0, t0, scratch);
This looks like a missing merge, but no big deal.

http://codereview.chromium.org/9190001/diff/9001/src/heap.cc
File src/heap.cc (right):

http://codereview.chromium.org/9190001/diff/9001/src/heap.cc#newcode5365
src/heap.cc:5365: // Setup the seed that is used to randomize the string hash
function.
AAAAArhg! :-)

http://codereview.chromium.org/9190001/diff/9001/src/ia32/code-stubs-ia32.cc
File src/ia32/code-stubs-ia32.cc (right):

http://codereview.chromium.org/9190001/diff/9001/src/ia32/code-stubs-ia32.cc#...
src/ia32/code-stubs-ia32.cc:5616: roots_address));
Oops, there's a missing SmiUntag here.  I fixed it in 10443 and included the
change here before committing.

http://codereview.chromium.org/9190001/diff/9001/src/objects.h
File src/objects.h (left):

http://codereview.chromium.org/9190001/diff/9001/src/objects.h#oldcode1906
src/objects.h:1906: // dictionary.  Returns the backing after conversion.
Strange removal of this comment, but no big deal.

http://codereview.chromium.org/9190001/diff/9001/src/objects.h
File src/objects.h (right):

http://codereview.chromium.org/9190001/diff/9001/src/objects.h#newcode2537
src/objects.h:2537: // I'm using map()->heap() to skip is_safe_to_read_maps
assertion.
This comment and the associated change should not be there.