gcc47 update to support libgcc*dylib move to libstdcxx in gcc48

[howarth@…]

The attached packaging removes the libstdcxx subport from gcc47 since gcc48 now contains it as well as implementing the changes to support the move of the libgcc*dylib files into the libstdcxx subpart. Also added patch to backport the nanosleep support for threads in c++11.

[howarth@…]

Portfile diff to deprecate libstdcxx subport in gcc47 and support the move of libgcc*dylib to libstdcxx subport in gcc48

[howarth@…]

backport of fix to support nanosleep in threads on c++11

[cooljeanius (Eric Gallager)]

Cc Me!

[howarth@…]

Confirmed that this packaging installs cleanly with the new gcc48 packaging and that the test case from ticket #38732 now compiles and runs properly using gcc47 ...

% g++-mp-4.7 -std=c++11 test.cc
% ./a.out
doing the test
success, result is 1

[howarth@…]

test case that demonstrates current gcc47 uses two unwinders

[ryandesign (Ryan Carsten Schmidt)]

This patch to remove the libstdcxx subport from the gcc47 port should be committed either before or at the same time as the libstdcxx subport is added to the gcc48 port using the patch in #38758, to avoid the indexing failure that would result from having two (sub)ports of the same name in the tree at the same time.