have jump,make_fcontext show up as importable

[haubi]

On AIX, building with aix-soname=svr4, nm is used to list public symbols
in object files. This fixes the assembly to have make_fcontext and
jump_fcontext show up as public symbols.

The problem actually shows up when linking the coroutine library against the context library when built with aix-soname=svr4.
However, except for this patch allowing to compile and link even coroutine, I'm unsure if the assembly is correct from all aspects, like alignment, TOC, and whether it works.

[olk]

thx, I've applied the patch to branch develop

[xantares]

hi @haubi, @olk,
I'm experiencing a similar issue with boost 1.58 for mingw64 (it was fine for 1.57):

gcc.link.dll bin.v2/libs/coroutine/build/gcc-mingw-mingw64/release/binary-format-pe/target-os-windows/threadapi-win32/threading-multi/libboost_coroutine-mt.dll.a
bin.v2/libs/coroutine/build/gcc-mingw-mingw64/release/binary-format-pe/target-os-windows/threadapi-win32/threading-multi/detail/coroutine_context.o:coroutine_context.cpp:(.text+0x4a): undefined reference to `_imp__make_fcontext'
bin.v2/libs/coroutine/build/gcc-mingw-mingw64/release/binary-format-pe/target-os-windows/threadapi-win32/threading-multi/detail/coroutine_context.o:coroutine_context.cpp:(.text+0xc7): undefined reference to `_imp__jump_fcontext'

I use this patch: http://pkgs.fedoraproject.org/cgit/mingw-boost.git/tree/boost-mingw.patch
how can I fix it for mingw too ?