cygwin g++: undefined reference to `___deregister_frame_info_bases'

[Billinghurst, David (CRTS)]

On cygwin, many g++ and libstdc++-v3 tests fail with error:

/usr/local/obj/gcc/gcc/libgcc.a(unwind-dw2-fde.o): In function
`_deregister_frame': 
/usr/local/src/gcc/gcc/unwind-pe.h(.text+0x49b): undefined reference to
`___deregister_frame_info_bases'

This happens on both trunk and branch.