[PING*2][C++ Patch, 4.8] Backport fix for c++/54537 to FSF 4.8

[Peter Bergner]

I'd like to ping*2 the following backport patch for the fix for PR54537.
This did bootstrap and regtest with no regressions on powerpc64-linux.

  http://gcc.gnu.org/ml/gcc-patches/2014-03/msg01148.html

Jonathan approved the library part, so I just need the front-end
change approved.

Peter