Fix Frame::AlignSavedCalleeRegisterSlots

Fix Frame::AlignSavedCalleeRegisterSlots

The return value is expected to be the number of padding slots added to the frame. However, the original logic would return -1 if padding was required, so insufficient stack space would be reserved.

This function now returns either 0 or 1, as the existing calling code expects.

BUG=

Committed: https://crrev.com/0a844bc0dc688097e0d895f21f0f70cb249290a7
Cr-Commit-Position: refs/heads/master@{#30994}

[jbramley, 2015-09-28 14:01:48]

jacob.bramley@arm.com changed reviewers:
+ bmeurer@chromium.org, ulan@chromium.org

[jbramley, 2015-09-28 14:01:48]

Note that this is hard to test; only a few tests touch this code and they don't
thoroughly check the integrity of the stack. (I'm not even sure how to do that.)

However, I have another patch in my pipeline which depends on the correct
behaviour of this function, so when that is ready the existing tests will cover
it.

[Benedikt Meurer, 2015-09-28 14:19:20]

Please write a longer explanation in the CL description. Otherwise LGTM

[Benedikt Meurer, 2015-09-29 02:52:40]

On 2015/09/28 14:19:20, Benedikt Meurer wrote:
> Please write a longer explanation in the CL description. Otherwise LGTM

Yes. Thanks.

[jbramley, 2015-09-29 07:25:12]

The CQ bit was checked by jacob.bramley@arm.com

[commit-bot: I haz the power, 2015-09-29 07:25:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1369303002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1369303002/1

[commit-bot: I haz the power, 2015-09-29 07:48:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-09-29 07:49:10]

Patchset 1 (id:??) landed as
https://crrev.com/0a844bc0dc688097e0d895f21f0f70cb249290a7
Cr-Commit-Position: refs/heads/master@{#30994}