VM: Load common VM constants from Thread on ARM and MIPS.

VM: Load common VM constants from Thread on ARM and MIPS.

This saves code size and also makes intrinsic code relocatable since
the UpdateStoreBuffer-stub is now called indirectly (loaded from THR)
instead of embedded as an immediate.

Also addressed feedback from previous CL.

BUG=
R=koda@google.com

Committed: https://github.com/dart-lang/sdk/commit/9bdab8ee2b9a3f52ef7e5e31468ae7553942e9a4

[Florian Schneider, 2015-07-08 14:16:18]

fschneider@google.com changed reviewers:
+ koda@google.com

[koda, 2015-07-08 14:50:34]

lgtm

https://codereview.chromium.org/1227733002/diff/1/runtime/vm/assembler_mips.cc
File runtime/vm/assembler_mips.cc (right):

https://codereview.chromium.org/1227733002/diff/1/runtime/vm/assembler_mips.c...
runtime/vm/assembler_mips.cc:472: } else if (object.InVMHeap() ||
!allow_constant_pool()) {
Oh, we actually have the check here, so I guess it's not too expensive then. So,
I again suggest adding it to OffsetFromThread

[Florian Schneider, 2015-07-09 08:50:36]

https://codereview.chromium.org/1227733002/diff/1/runtime/vm/assembler_mips.cc
File runtime/vm/assembler_mips.cc (right):

https://codereview.chromium.org/1227733002/diff/1/runtime/vm/assembler_mips.c...
runtime/vm/assembler_mips.cc:472: } else if (object.InVMHeap() ||
!allow_constant_pool()) {
On 2015/07/08 14:50:34, koda wrote:
> Oh, we actually have the check here, so I guess it's not too expensive then.
So,
> I again suggest adding it to OffsetFromThread

Done.

[Florian Schneider, 2015-07-09 09:12:56]

Committed patchset #2 (id:20001) manually as
9bdab8ee2b9a3f52ef7e5e31468ae7553942e9a4 (presubmit successful).