Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r260311, r260831:

gcc: Add support for Apple's Block extension

Block objects [1] are a C-level syntactic and runtime feature. They
are similar to standard C functions, but in addition to executable
code they may also contain variable bindings to automatic (stack)
or managed (heap) memory. A block can therefore maintain a set of
state (data) that it can use to impact behavior when executed.

This port is based on Apple's GCC 5646 with some bugfixes from
Apple GCC 5666.3. It has some small differences with the support
in clang, which remains the recommended compiler.

Perhaps the most notable difference is that in GCC __block is not
actually a keyword, but a macro. There may be workaround for this
issue in the future. Other issues can be consulted in the clang
documentation [2]

For better compatiblity with Apple's GCC and llvm-gcc, some related
fixes and features from Apple have been included. Support for the
non-standard nested functions in GCC is now off by default.

No effort was made to update the ObjC support since FreeBSD doesn't
carry ObjC in the base system but some of the code crept in and
was more difficult to remove than to adjust.

References:
[1]
https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Blocks/Articles/00_Introduction.html
[2]
http://clang.llvm.org/compatibility.html#block-variable-initialization

Obtained from: Apple GCC 4.2

MFC r258017, r258429, r258748, r258817:

Merge updates from FSF pre4.3 GCC inspired on Apple's gcc:

Updates to libiberty and mangling.
New align attribute.
Merge Apple updates to libstdc++.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Clean up hardcoded ar(1) flags in the tree to use the global ARFLAGS in
share/mk/sys.mk instead.

This is part of a medium term project to permit deterministic builds of
FreeBSD.

Submitted by: Erik Cederstrand <erik@cederstrand.dk>
Reviewed by: imp, toolchain@
Approved by: cperciva
MFC after: 2 weeks

Fix clang compile warnings.

Approved by: philip (mentor)

This commit was generated by cvs2svn to compensate for changes in r171831,
which included commits to RCS files with non-trunk default branches.

Re-add local FreeBSD change: prefer /tmp to /var/tmp and /usr/tmp
for temporary files.

This commit was generated by cvs2svn to compensate for changes in r169695,
which included commits to RCS files with non-trunk default branches.