Add user_regs_struct and user_fpsimd_struct for aarch64 on Android.

Add user_regs_struct and user_fpsimd_struct for aarch64 on Android.

Android's sys/user.h is missing user_regs_struct and user_fpsimd_struct.
Add them to the Android specific user.h used by breakpad to workaround
Android / glibc compatibility issues.

A bug has been filed on the Android NDK team to add the missing structures to
the NDK, at which point this hack can be removed.

Also remove the mxcsr_mask hack on x64, which is no longer required since
we have moved to the r10d NDK which fixes this issue.

R=primiano@chromium.org

Committed: https://code.google.com/p/google-breakpad/source/detail?r=1495

[rmcilroy, 2015-08-20 14:10:49]

rmcilroy@chromium.org changed reviewers:
+ primiano@chromium.org

[rmcilroy, 2015-08-20 14:10:49]

Primiano, could you take a look please?

[Primiano Tucci (use gerrit), 2015-08-20 14:25:09]

Many thanks for the fix.
LGTM with 1 question.
I can re-roll after you land this.

https://codereview.chromium.org/1291983003/diff/1/src/common/android/include/...
File src/common/android/include/sys/user.h (right):

https://codereview.chromium.org/1291983003/diff/1/src/common/android/include/...
src/common/android/include/sys/user.h:56: struct user_regs_struct {
Shouldn't these be guarded by a ifdef cplusplus + extern "C"  ?

[rmcilroy, 2015-08-20 14:29:03]

https://codereview.chromium.org/1291983003/diff/1/src/common/android/include/...
File src/common/android/include/sys/user.h (right):

https://codereview.chromium.org/1291983003/diff/1/src/common/android/include/...
src/common/android/include/sys/user.h:56: struct user_regs_struct {
On 2015/08/20 14:25:09, Primiano Tucci wrote:
> Shouldn't these be guarded by a ifdef cplusplus + extern "C"  ?

Yup, thanks! Done.

[rmcilroy, 2015-08-20 14:30:45]

Committed patchset #2 (id:20001) manually as 1495 (presubmit successful).