Building a lot of glibc files trigger warnings like so:
.../ucontext.h:52:25: warning: variably modified '_pad' at file scope
The ia64 header protects the use of __builtin_offsetof by a C++
compiler, but this builtin works just fine with C compilers, so
allow it to be used there too.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
91e5f2e441