cmd/vendor/golang.org/x/arch: revendor at commit 98fd8d9

Pick up CL 85476 to fix #23237.

Updates #23237.

Change-Id: I31a48ef39ce90bc1424334762452281ae706d273
Reviewed-on: https://go-review.googlesource.com/85495
Reviewed-by: Brad Fitzpatrick <[email protected]>

Author: cherrymui

src/cmd/vendor/golang.org/x/arch/arm64/arm64asm/objdumpext_test.go

@@ -15,20 +15,26 @@
 		{
 			"canonical": "golang.org/x/arch/x86/x86asm",
 			"local": "golang.org/x/arch/x86/x86asm",
-			"revision": "58ea1a195b1a354bcd572b7ef6bbbd264dc63732",
-			"revisionTime": "2017-02-16T08:17:04Z"
+			"revision": "98fd8d9907002617e6000a77c0740a72947ca1c2"
+			"revisionTime": "2017-12-26T02:13:20Z"
 		},
 		{
 			"canonical": "golang.org/x/arch/arm/armasm",
 			"local": "golang.org/x/arch/arm/armasm",
-			"revision": "ad6a463afcf9bd5b38c81fa9ba612dae11859d40",
-			"revisionTime": "2015-08-28T15:42:14Z"
+			"revision": "98fd8d9907002617e6000a77c0740a72947ca1c2"
+			"revisionTime": "2017-12-26T02:13:20Z"
 		},
 		{
 			"canonical": "golang.org/x/arch/ppc64/ppc64asm",
 			"local": "golang.org/x/arch/ppc64/ppc64asm",
-			"revision": "4831b0a617f7a819d4bf3c877d8e827d0283542c",
-			"revisionTime": "2016-10-12T18:28:04Z"
+			"revision": "98fd8d9907002617e6000a77c0740a72947ca1c2"
+			"revisionTime": "2017-12-26T02:13:20Z"
+		},
+		{
+			"canonical": "golang.org/x/arch/arm64/arm6464asm",
+			"local": "golang.org/x/arch/arm64/arm64asm",
+			"revision": "98fd8d9907002617e6000a77c0740a72947ca1c2"
+			"revisionTime": "2017-12-26T02:13:20Z"
 		}
 	]
 }