Optimize some vfp comparisons to integer ones. This patch implements the...

Optimize some vfp comparisons to integer ones. This patch implements the simplest case when the following conditions are met:
1. The arguments are f32.
2. The arguments are loads and they have no uses other than the comparison.
3. The comparison code is EQ or NE.

e.g.
        vldr.32 s0, [r1]
        vldr.32 s1, [r0]
        vcmpe.f32       s1, s0
        vmrs    apsr_nzcv, fpscr
	beq     LBB0_2
=>
        ldr     r1, [r1]
        ldr     r0, [r0]
        cmp     r0, r1
        beq     LBB0_2

More complicated cases will be implemented in subsequent patches.

llvm-svn: 107852