[llvm] [MIPS] Implement llvm.fminimum and llvm.fmaximum with f32/f64 (PR #89907)

[YunQiang Su via llvm-commits]

wzssyqa wrote:

I figure out a pre-R6 asm code

```
xm:
	.frame	$sp,0,$31		# vars= 0, regs= 0/0, args= 0, gp= 0
	.mask	0x00000000,0
	.fmask	0x00000000,0
	.set	noreorder
	.set	nomacro
	c.lt.d	$fcc0,$f14,$f12
	bc1t	$fcc0,$L6
	mov.d	$f0,$f12

	c.lt.d	$fcc0,$f12,$f14
	bc1t	$fcc0,$L6
	mov.d	$f0,$f14

	c.eq.d $fcc0,$f14,$f12
	bc1f	$fcc0,$L4
	mfhc1	$t4,$f14
	bltz	$t4,$L6
	mov.d	$f0,$f12

	mfhc1	$t4,$f12
	bltz	$t4,$L6
	mov.d	$f0,$f14

$L4:
	mtc1	$0,$f4
	mthc1	$0,$f4
	c.un.d	$fcc0,$f12,$f4
	bc1t	$fcc0,$L6
	mov.d	$f0,$f12

	# we have $f14 already
$L6:
	jr	$31
	nop
```

I will feed back it to glibc.

https://github.com/llvm/llvm-project/pull/89907