Fix brk/sbrk error checking.

Note that the kernel returns the current break on error or if the requested
break is smaller than the minimum break, or the new break. I don't know where
we got the idea that the kernel could return -1.

Also optimizes the query case.

Also hides an accidentally-exported symbol for LP64.

Change-Id: I0fd6b8b14ddf1ae82935c0c3fc610da5cc74932e
Merge "Fix brk/sbrk error checking."
Pass si_code through to debuggerd.

Because we re-raise various signals, we corrupt the si_code that debuggerd
sees when it ptraces our siginfo. One possible solution (shown here) is to
pass the original si_code value in the message we send to debuggerd.

Change-Id: I76f9aa2c0442e5cab611d132532409e700383907
Merge "Pass si_code through to debuggerd."
Don't use so much stack in tzcode.

Bug: 14313703
Bug: https://code.google.com/p/android/issues/detail?id=61130
Change-Id: Id9b240fce20d4a6f2660792070e02b2b5f287655
Merge "Don't use so much stack in tzcode."
Merge remote-tracking branch 'aosp/master' into fml-master