jsutil: Remove unused files for Go 1.12

internal/jsutil/go112_js.go

@@ -1,45 +0,0 @@
-// Copyright 2019 The Ebiten Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-// +build !go1.13
-
-package jsutil
-
-import (
-	"syscall/js"
-)
-
-func Uint8ArrayToSlice(value js.Value) []byte {
-	// Note that TypedArrayOf cannot work correcly on Wasm.
-	// See https://github.com/golang/go/issues/31980
-
-	s := make([]byte, value.Get("byteLength").Int())
-	a := js.TypedArrayOf(s)
-	a.Call("set", value)
-	a.Release()
-	return s
-}
-
-func ArrayBufferToSlice(value js.Value) []byte {
-	return Uint8ArrayToSlice(js.Global().Get("Uint8Array").New(value))
-}
-
-func CopySliceToJS(dst js.Value, src interface{}) {
-	// Note that TypedArrayOf cannot work correcly on Wasm.
-	// See https://github.com/golang/go/issues/31980
-
-	a := js.TypedArrayOf(src)
-	dst.Call("set", a)
-	a.Release()
-}