deps: cherry-pick 2b4c9c1 from v8 upstream

Original commit message:

S390:Update inline asm constraint in test-platform
The GetStackPointer() routine in test-platform uses an inline
assembly code to store the current stack pointer value into a static
variable sp_addr.  The existing asm code for S390 uses an ST/STG
instruction, with the memory operand associated with the general ('=g')
constraint to sp_addr.

On GCC 4.8.5, the GCC compiler got confused and treated sp_addr as
an integer operand instead of memory operand, resulting in a store
being emitted that writes to an invalid meory location.

Given the specific store instructions being inlined here, we should
restict the sp_addr operand to explicitly be a memory operand using '=m'
instead of '=g'.

R=bmeurer@chromium.org,jkummerow@chormium.org,rmcilroy@chromium.org,yangguo@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2158523002
Cr-Commit-Position: refs/heads/master@{#37809}

Fixes: https://github.com/nodejs/node/issues/7659
PR-URL: https://github.com/nodejs/node/pull/7771


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Ali Ijaz Sheikh <ofrobots@google.com>