Patch to fix PR9861

[TJ Laurenzo]

Andrew Haley wrote:
> I wonder what this does to debugging.  I'm going to try it now.


If you build gdb with the patched cp-demangle.c the only difference
*should* be that demangled names will include the return type (without
cp-demangle.c patched, you will only see mangled names).  I have not
tested this against gdb so I am interested to know how it goes.

I have tested this against binutils by applying the cp-demangle.c
patch and verifying that demangling names in object files works
properly (ie.  nm -C).  I have also added a couple of test cases to
libiberty that exercise this change.

TJ