MFC r286074:
GCC: Add a new option "-fstack-protector-strong"

This includes additional functions to be protected: those that
have local array definitions, or have references to local frame
addresses. This is a new option in GCC-4.9 that was relicensed
by Han Shen from Google under GPLv2.

Obtained from: OpenBSD (2014-01-14)

MFC r264121;
gcc: define __block when block support is enabled

This mimics the behaviour in clang and lets us build cleanly
the libdispatch port on platforms where the base gcc is still
the default compiler.

Bump __FreeBSD_version for ports.

Tested by: theraven

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 r286074:
GCC: Add a new option "-fstack-protector-strong"

This includes additional functions to be protected: those that
have local array definitions, or have references to local frame
addresses. This is a new option in GCC-4.9 that was relicensed
by Han Shen from Google under GPLv2.

Obtained from: OpenBSD (2014-01-14)

MFC r264121;
gcc: define __block when block support is enabled

This mimics the behaviour in clang and lets us build cleanly
the libdispatch port on platforms where the base gcc is still
the default compiler.

Bump __FreeBSD_version for ports.

Tested by: theraven

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