Do not store fp and sp values in TickSample

Do not store fp and sp values in TickSample

Their values are not used neither by the tick processor nor by CpuProfiler so it is just a waste of space.

TickSample used to be a transport for grabbed register values to TickSample::Trace, now they are passed in a special structure RegisterState which is allocated on the stack for the sampling period.

Some common pieces were moved from platform-dependent code into Sampler::SampleStack and TickSample::Init.
 
BUG=None
R=jkummerow@chromium.org, loislo@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=15484

[loislo, 2013-07-03 09:06:12]

lgtm

[Jakob Kummerow, 2013-07-03 14:12:31]

lgtm

https://codereview.chromium.org/18620002/diff/2001/src/frames.cc
File src/frames.cc (right):

https://codereview.chromium.org/18620002/diff/2001/src/frames.cc#newcode220
src/frames.cc:220: StackFrameIteratorBase(isolate, false),
nit: while you're here, please move the ':' onto this line and increase
indentation accordingly.

[yurys, 2013-07-03 14:16:41]

https://codereview.chromium.org/18620002/diff/2001/src/frames.cc
File src/frames.cc (right):

https://codereview.chromium.org/18620002/diff/2001/src/frames.cc#newcode220
src/frames.cc:220: StackFrameIteratorBase(isolate, false),
On 2013/07/03 14:12:31, Jakob wrote:
> nit: while you're here, please move the ':' onto this line and increase
> indentation accordingly.

Done.

[yurys, 2013-07-03 16:21:10]

Committed patchset #4 manually as r15484 (presubmit successful).