Improve <sys/cdefs.h>.

Fix and use __RENAME (and lose ___RENAME --- two underscores should be
enough for anybody). This was the point of this change, because I want
to use __RENAME to support the two basename variants and the two
strerror_r variants.

Lose a bunch of macros that weren't being used.

Lose three dead files from the DNS code.

Change-Id: I3ef645c566b16a52217bc2e68c7d54b37c7c9522
Merge "Improve <sys/cdefs.h>."
Fix <features.h> (_BSD_SOURCE and _GNU_SOURCE).

<features.h> is supposed to take user-settable stuff like _GNU_SOURCE
and _BSD_SOURCE and turn them into __USE_GNU and __USE_BSD for use in
the C library headers. Instead, bionic used to unconditionally define
_BSD_SOURCE and _GNU_SOURCE, and then test _GNU_SOURCE in the header
files (which makes no sense whatsoever).

Bug: 14659579
Change-Id: Ice4cf21a364ea2e559071dc8329e995277d5b987
Merge "Fix <features.h> (_BSD_SOURCE and _GNU_SOURCE)."
Hide C++ stuff in libc. Put it back in libstdc++.

Bug: 17062445
Change-Id: I027b186719654c2865b08c3fa83f90fa00c1e838
Merge "Hide C++ stuff in libc. Put it back in libstdc++."
Merge "malloc_usable_size returns the original size."
malloc_usable_size returns the original size.

Bug: 16874447

(cherry picked from commit 59c1ee44d0a560a754513fab12641c8a57a20d9e)

Change-Id: I70839632974367c8b9893fb1f9c5ee4364608470
Fix leak_realloc, copy entire allocation.

Bug: 16874447

(cherry picked from commit 5df0839cea98bd8c37d8dba5b94b98e99c681a94)

Change-Id: I9280505c0c1c3b5da24ba590448dcd6e7a230406
Merge "Fix leak_realloc, copy entire allocation."
Expose android_set_abort_message().

Removes the leading underscores from __android_set_abort_message() and
moves its declaration into a public header file.

Bug: 17059126
Change-Id: I470c79db47ec783ea7a54b800f8b78ecbe7479ab
Merge "Expose android_set_abort_message()."
Missing #include <sys/cdefs.h>.

Needed for __BEGIN_DECLS/__END_DECLS. Currently fine because it's being
included after other files that do this.

Change-Id: I1f12368fc461f6ef5ca90992cf19f317f0b5d7af
Merge "Missing #include <sys/cdefs.h>."
Revert "Add support for protected local symbol lookup."

This reverts commit d97e9f546ea195686a78e539315b273393609b9e.

Bug: 17107521
(cherry picked from commit 9419420919ea846bbad5510850c7aaec95021648)

Change-Id: I1a6df946ac8075699e77d68ffa6ac4a21b88e4bf
Merge "Revert "Add support for protected local symbol lookup.""
Fix _BSD_SOURCE/__USE_BSD.

Bug: 14659579
Change-Id: I80ec9584f054c02d1078828f6bca759c42bc1d4c
Merge "Fix _BSD_SOURCE/__USE_BSD."
Remove unused defines from <features.h>.

Bug: 14659579
Change-Id: I2ab02b13cafe3faad31248b843d39ab2cdbfeb91
Merge "Remove unused defines from <features.h>."