Work around a gcc bug. This fixes feholdexcept() et al. at -O1.

Symptoms of the problem included assembler warnings and
nondeterministic runtime behavior when a fe*() call that affects the
fpsr is closely followed by a float point op.

The bug (at least, I think it's a bug) is that gcc does not insert a
break between a volatile asm and a dependent instruction if the
volatile asm came from an inlined function.  Volatile asms seem to be
fine in other circumstances, even without -mvolatile-asm-stop, so
perhaps the compiler adds the stop bits before inlining takes place.
The problem does not occur at -O0 because inlining is disabled, and it
doesn't happen at -O2 because -fschedule-insns2 knows better.

lib/msun/ia64/fenv.h

@@ -61,7 +61,7 @@ extern const fenv_t	__fe_dfl_env;
 #define	_FPUSW_SHIFT	13
 
 #define	__stfpsr(__r)	__asm __volatile("mov %0=ar.fpsr" : "=r" (*(__r)))
-#define	__ldfpsr(__r)	__asm __volatile("mov ar.fpsr=%0" : : "r" (__r))
+#define	__ldfpsr(__r)	__asm __volatile("mov ar.fpsr=%0;;" : : "r" (__r))
 
 static __inline int
 feclearexcept(int __excepts)