remove build flags for unsupported versions
MODIFY
internal/asm/f64/gemvN_amd64.s
internal/asm/f64/gemvN_amd64.s
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-//+build go1.8,!noasm,!appengine
+//+build !noasm,!appengine
#include "textflag.h"

MODIFY
internal/asm/f64/gemvT_amd64.s
internal/asm/f64/gemvT_amd64.s
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-//+build go1.8,!noasm,!appengine
+//+build !noasm,!appengine
#include "textflag.h"

MODIFY
internal/asm/f64/gemv_test.go
internal/asm/f64/gemv_test.go
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-// +build go1.7
-
package f64
import (

remove build flags for unsupported versions