cmd/dist: enable cgo and external linking on linux/mips64x

Fixes #14126

Change-Id: I21c8e06c01d3ef02ee09dc185d4443e2da8fd52b
Reviewed-on: https://go-review.googlesource.com/19809Reviewed-by: Minux Ma <minux@golang.org>

src/cmd/dist/build.go

@@ -1096,8 +1096,8 @@ var cgoEnabled = map[string]bool{
 	"linux/arm64":     true,
 	"linux/ppc64":     false,
 	"linux/ppc64le":   true,
-	"linux/mips64":    false,
-	"linux/mips64le":  false,
+	"linux/mips64":    true,
+	"linux/mips64le":  true,
 	"linux/s390x":     true,
 	"android/386":     true,
 	"android/amd64":   true,

src/cmd/dist/test.go

@@ -640,7 +640,7 @@ func (t *tester) extLink() bool {
 		"darwin-arm", "darwin-arm64",
 		"dragonfly-386", "dragonfly-amd64",
 		"freebsd-386", "freebsd-amd64", "freebsd-arm",
-		"linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le",
+		"linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le", "linux-mips64", "linux-mips64le",
 		"netbsd-386", "netbsd-amd64",
 		"openbsd-386", "openbsd-amd64",
 		"windows-386", "windows-amd64":