Abstract out fetching of break_address in debug mode

Abstract out fetching of break_address in debug mode

If the platform has a variable length call sequence
more than simple offset math is required. This can
be true with out of line constant pools on PowerPC.

BUG=
R=yangguo@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=22935

[andrew_low, 2014-07-29 18:56:30]

As per comments in https://codereview.chromium.org/422063005/ I've provided an
abstraction to fetching the break address in the case when the call sequence may
be variable in length.

[danno, 2014-07-30 09:47:51]

Yang, could you please review/land this for Andrew

[rmcilroy, 2014-07-30 10:05:36]

https://codereview.chromium.org/427863003/diff/20001/src/arm/assembler-arm.h
File src/arm/assembler-arm.h (right):

https://codereview.chromium.org/427863003/diff/20001/src/arm/assembler-arm.h#...
src/arm/assembler-arm.h:814: inline static Address
break_address_from_break_address(Address pc);
Please use the INLINE() macro and move up to be below
return_address_from_call_start (for all arches).  Also, I think it should be
called break_address_from_return_address.

[andrew_low, 2014-07-30 14:06:46]

Thanks for the feedback, I've modified the patch as suggested

https://codereview.chromium.org/427863003/diff/20001/src/arm/assembler-arm.h
File src/arm/assembler-arm.h (right):

https://codereview.chromium.org/427863003/diff/20001/src/arm/assembler-arm.h#...
src/arm/assembler-arm.h:814: inline static Address
break_address_from_break_address(Address pc);
On 2014/07/30 10:05:36, rmcilroy wrote:
> Please use the INLINE() macro and move up to be below
> return_address_from_call_start (for all arches).  Also, I think it should be
> called break_address_from_return_address.

Done.

[Yang, 2014-07-30 14:43:31]

LGTM with a tiny nit.

https://codereview.chromium.org/427863003/diff/40001/src/ia32/assembler-ia32-...
File src/ia32/assembler-ia32-inl.h (right):

https://codereview.chromium.org/427863003/diff/40001/src/ia32/assembler-ia32-...
src/ia32/assembler-ia32-inl.h:483: 
two new lines here please.

[andrew_low, 2014-07-30 15:18:53]

Fixed formatting.

https://codereview.chromium.org/427863003/diff/40001/src/ia32/assembler-ia32-...
File src/ia32/assembler-ia32-inl.h (right):

https://codereview.chromium.org/427863003/diff/40001/src/ia32/assembler-ia32-...
src/ia32/assembler-ia32-inl.h:483: 
On 2014/07/30 14:43:30, Yang wrote:
> two new lines here please.

Done.

[Yang, 2014-08-06 13:57:12]

Committed patchset #4 manually as 22935 (presubmit successful).