style: put the repository assembly in gasm fmt canonical form

Assisted-by: GLM 5.3 Flash

testdata/verify/movimm_arm64.s

@@ -5,17 +5,17 @@
 
 // movimm exercises MOV with various immediate values.
 TEXT ·movimm(SB), NOSPLIT, $0-0
-	MOVD	$0, R0
-	MOVD	$1, R1
-	MOVD	$42, R2
-	MOVD	$255, R3
-	MOVD	$256, R4
-	MOVD	$0xFFFF, R5
-	MOVD	$0x12345678, R6
-	MOVD	$0x123456789ABCDEF0, R7
-	MOVD	$-1, R8
-	MOVD	$-2, R9
-	MOVW	$0, R10
-	MOVW	$100, R11
-	MOVW	$0x12345, R12
+	MOVD $0, R0
+	MOVD $1, R1
+	MOVD $42, R2
+	MOVD $255, R3
+	MOVD $256, R4
+	MOVD $0xFFFF, R5
+	MOVD $0x12345678, R6
+	MOVD $0x123456789ABCDEF0, R7
+	MOVD $-1, R8
+	MOVD $-2, R9
+	MOVW $0, R10
+	MOVW $100, R11
+	MOVW $0x12345, R12
 	RET