Compile this:

void foo(float a, int *b) { *b = a; }

to this:

_foo:
        fctiwz f0, f1
        stfiwx f0, 0, r4
        blr

instead of this:

_foo:
        fctiwz f0, f1
        stfd f0, -8(r1)
        lwz r2, -4(r1)
        stw r2, 0(r4)
        blr

This implements CodeGen/PowerPC/stfiwx.ll, and also incidentally does the
right thing for GCC bugzilla 26505.

llvm-svn: 26447