Clean up warnings in libstdc++.

Change-Id: Ie71a2fdf227e7a5fc9a446bb1be110da9b3a4280
Clean up various warnings in bionic.

Change-Id: Ic57541d0a567fd4ae79f0ad59b2ffde1130eb7d2
Merge "Clean up various warnings in bionic."
Merge "Clean up warnings in libstdc++."
bionic: fix __set_errno for arm64 syscalls that return a 64-bit value

bionic/libc/arch-arm64/syscalls/read.S ends with:
    b.hi __set_errno
    ret
END(read)

If __set_errno returns int, it will set w0 to 0xFFFFFFFF, which means
x0 is 0x00000000FFFFFFFF.  When interpreted as a ssize_t that is
INT_MAX, not -1.

Change __set_errno to return long, which will cause x0 to be set instead
of w0.

Change-Id: I9f9ea0f2995928d2ea240eb2ff7758ecdf0ff412
Merge "bionic: fix __set_errno for arm64 syscalls that return a 64-bit value"
Fix x86 build.

Change-Id: Iee6e5884288f7da6c955694cfe32fecfd9c9e263
Merge "Fix x86 build."
Merge branch 'master' of https://android.googlesource.com/platform/bionic into HEAD