i#2173: Fix failure to restore REG_PRESERVED_1 in test_nzcv_pos.

Commit log for first patchset:
---------------
i#2173: Fix failure to restore REG_PRESERVED_1 in test_nzcv_pos.

On ARM and AArch64 we use the macros SAVE_REGS and RESTORE_REGS to save
and restore REG_PRESERVED_1 and the link register, LR. The function
test_nzcv_pos no longer uses REG_PRESERVED_2, so that macro is removed,
for now.

Fixes #2173
---------------

[bruening, 2017-02-13 16:28:26]

The names could be improved, otherwise LGTM

Please consider trying github pull requests to get Windows testing pre-commit,
though that workflow is still being finalized and has some drawbacks.  Long-term
we are likely to drop Rietveld support and may move toward feature branches and
pull requests.

https://codereview.appspot.com/311660043/diff/1/core/arch/asm_defines.asm
File core/arch/asm_defines.asm (right):

https://codereview.appspot.com/311660043/diff/1/core/arch/asm_defines.asm#new...
core/arch/asm_defines.asm:377: #  define SAVE_REGS    push {REG_PRESERVED_1, LR}
The name seems vague: SAVE_PRESERVED_REGS sounds much more descriptive

https://codereview.appspot.com/311660043/diff/1/core/arch/asm_defines.asm#new...
core/arch/asm_defines.asm:378: #  define RESTORE_REGS pop  {REG_PRESERVED_1, LR}
Ditto: RESTORE_PRESERVED_REGS

[Edmund.Grimley.Evans, 2017-02-15 11:37:53]

Committed as
https://github.com/DynamoRIO/dynamorio/commit/1abab1e4997485d0ccb19bff7c09e66...

Final commit log: 
---------------
i#2173: Fix failure to restore REG_PRESERVED_1 in test_nzcv_pos.

On ARM and AArch64 we use the macros SAVE_PRESERVED_REGS and
RESTORE_PRESERVED_REGS to save and restore REG_PRESERVED_1 and the link
register, LR. The function test_nzcv_pos no longer uses REG_PRESERVED_2,
so that macro is removed, for now.

Fixes #2173

Review-URL: https://codereview.appspot.com/311660043
---------------

[Edmund.Grimley.Evans, 2017-02-15 11:42:13]

It's not really committed:

remote: Resolving deltas: 100% (8/8), completed with 8 local objects.
remote: error: GH006: Protected branch update failed for refs/heads/master.
remote: error: 2 of 2 required status checks are expected. At least one approved
review is required
To https://github.com/DynamoRIO/dynamorio.git
 ! [remote rejected] HEAD -> master (protected branch hook declined)
error: failed to push some refs to 'https://github.com/DynamoRIO/dynamorio.git'

Where is the latest workflow described?

[Edmund.Grimley.Evans, 2017-02-15 13:29:17]

I've created https://github.com/DynamoRIO/dynamorio/pull/2186. I hope that's
right.

[bruening, 2017-02-15 15:03:37]

On 2017/02/15 11:42:13, Edmund.Grimley.Evans wrote:
> It's not really committed:
> 
> remote: Resolving deltas: 100% (8/8), completed with 8 local objects.
> remote: error: GH006: Protected branch update failed for refs/heads/master.
> remote: error: 2 of 2 required status checks are expected. At least one
approved
> review is required
> To https://github.com/DynamoRIO/dynamorio.git
>  ! [remote rejected] HEAD -> master (protected branch hook declined)
> error: failed to push some refs to
'https://github.com/DynamoRIO/dynamorio.git'

The settings are a little confusing: it seemed like it would allow a direct push
and only put constraints on pull requests, but apparently it disallows a direct
push (the wording is disallowing "force pushes").

> Where is the latest workflow described?

I sent an announcement email to dynamorio-devs -- did you see that email?

[Edmund.Grimley.Evans, 2017-02-15 15:20:53]

> I sent an announcement email to dynamorio-devs -- did you see that email?

Yes. What should I do next?

[bruening, 2017-02-15 17:43:59]

On 2017/02/15 15:20:53, Edmund.Grimley.Evans wrote:
> > I sent an announcement email to dynamorio-devs -- did you see that email?
> 
> Yes. What should I do next?

I saw https://github.com/DynamoRIO/dynamorio/pull/2186 and approved and
fast-forward-merged it in.  See the comments there about the branch location and
name conventions.