cmd/internal/obj/arm: fix wrong encoding of NMULAF/NMULAD/NMULSF/NMULSD

NMULAF/NMULAD/NMULSF/NMULSD are incorrectly encoded by the arm
assembler.

Instruction            Right binary      Current wrong binary
"NMULAF	F5, F6, F7"    0xee167a45        0xee167a05
"NMULAD	F5, F6, F7"    0xee167b45        0xee167b05
"NMULSF	F5, F6, F7"    0xee167a05        0xee167a45
"NMULSD	F5, F6, F7"    0xee167b05        0xee167b45

This patch fixes this issue.

fixes issue #23212

Change-Id: Ic9c203f92c34b90d6eef492a694c0e95b4d479c5
Reviewed-on: https://go-review.googlesource.com/85116Reviewed-by: Cherry Zhang <cherryyz@google.com>
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/asm/internal/asm/testdata/armv6.s

@@ -26,10 +26,10 @@ TEXT	foo(SB), DUPOK|NOSPLIT, $0
 	MULAD	F5, F6, F7    // 057b06ee
 	MULSF	F5, F6, F7    // 457a06ee
 	MULSD	F5, F6, F7    // 457b06ee
-	NMULAF	F5, F6, F7    // 057a16ee
-	NMULAD	F5, F6, F7    // 057b16ee
-	NMULSF	F5, F6, F7    // 457a16ee
-	NMULSD	F5, F6, F7    // 457b16ee
+	NMULAF	F5, F6, F7    // 457a16ee
+	NMULAD	F5, F6, F7    // 457b16ee
+	NMULSF	F5, F6, F7    // 057a16ee
+	NMULSD	F5, F6, F7    // 057b16ee
 	FMULAF  F5, F6, F7    // 057aa6ee
 	FMULAD  F5, F6, F7    // 057ba6ee
 	FMULSF  F5, F6, F7    // 457aa6ee

src/cmd/internal/obj/arm/asm5.go

@@ -2940,13 +2940,13 @@ func (c *ctxt5) oprrr(p *obj.Prog, a obj.As, sc int) uint32 {
 	case AMULSF:
 		return o | 0xe<<24 | 0xa<<8 | 0x4<<4
 	case ANMULAD:
-		return o | 0xe<<24 | 0x1<<20 | 0xb<<8
+		return o | 0xe<<24 | 0x1<<20 | 0xb<<8 | 0x4<<4
 	case ANMULAF:
-		return o | 0xe<<24 | 0x1<<20 | 0xa<<8
+		return o | 0xe<<24 | 0x1<<20 | 0xa<<8 | 0x4<<4
 	case ANMULSD:
-		return o | 0xe<<24 | 0x1<<20 | 0xb<<8 | 0x4<<4
+		return o | 0xe<<24 | 0x1<<20 | 0xb<<8
 	case ANMULSF:
-		return o | 0xe<<24 | 0x1<<20 | 0xa<<8 | 0x4<<4
+		return o | 0xe<<24 | 0x1<<20 | 0xa<<8
 	case AFMULAD:
 		return o | 0xe<<24 | 0xa<<20 | 0xb<<8
 	case AFMULAF: