Add C11 <stdatomic.h>.

Bug: 14903517
Change-Id: I631dbfdaa698cf7fea8e3b5e18a32586383e62a5
Restore __srget and __swbuf for LP32.

Anthony King <anthonydking@slimroms.net> reports that for Grouper the
Nvidia GL blobs need access to __swbuf. This is because the old <stdio.h>
had inline getc and putc implementations that directly referred to these
symbols.

Change-Id: I11a7b5550018ecc93d8f195c99857759669b2906
Merge "Add C11 <stdatomic.h>."
Revert "Expose __swbuf and __srget"

This reverts commit 5350b51d4771aaabd6b710c02fb1ee78e6bc670c.
Restore __srget and __swbuf for LP32.

Anthony King <anthonydking@slimroms.net> reports that for Grouper the
Nvidia GL blobs need access to __swbuf. This is because the old <stdio.h>
had inline getc and putc implementations that directly referred to these
symbols.

Change-Id: I11a7b5550018ecc93d8f195c99857759669b2906
Merge "Restore __srget and __swbuf for LP32."
Restore __srefill for LP32.

The NDK apparently includes an android_support.a library that
refers to __srefill in its copy of the vsnprintf implementation.

Bug: 15249361
Change-Id: Ic2cf6f21290b3146c42fbe0624f5e4d54f6194b4
Merge "Restore __srefill for LP32."
Use __typeof__() instead of typeof()

typeof() is a gcc builtin and is not always available (such as clang when
-std=c*). Both gcc and clang always expose __typeof__(), so just use that.

Change-Id: I75e2a990acc35f6f39b2c353f6548100ec03c67f
Merge "Use __typeof__() instead of typeof()"
Clear the return address register in __bionic_clone.

The unwinder will end up on the parent thread's stack if the return
address register is not cleared.

Bug: 14270816
Bug: 15195760
Change-Id: Iebcdf5cc881cad245643bb193760de35eb7f8b19
Merge "Clear the return address register in __bionic_clone."
Expose __srefill for LP64 until we can fix the NDK.

The LP64 has a duplicate copy of part of stdio, and relies
on bionic supplying this part. We should remove the hack from
the NDK, at least for LP64, and then revert this.

Bug: 15291317
Change-Id: I75e06e130188ca0aeb9d50dfe3a3e48a1d3968b7
Merge "Expose __srefill for LP64 until we can fix the NDK."
auto-merger: merge in from aosp/master

Conflicts:
	libc/stdio/local.h