internal/unsafe: get rid of GoString

The only users were GOOS=windows code, which can use
golang.org/x/sys/windows.BytePtrToString instead.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

internal/egl/egl_windows.go

@@ -11,7 +11,6 @@ import (
 	syscall "golang.org/x/sys/windows"
 
 	"gioui.org/internal/gl"
-	gunsafe "gioui.org/internal/unsafe"
 )
 
 type (
@@ -154,7 +153,7 @@ func eglTerminate(disp _EGLDisplay) bool {
 
 func eglQueryString(disp _EGLDisplay, name _EGLint) string {
 	r, _, _ := _eglQueryString.Call(uintptr(disp), uintptr(name))
-	return gunsafe.GoString(gunsafe.SliceOf(r))
+	return syscall.BytePtrToString((*byte)(unsafe.Pointer(r)))
 }
 
 // issue34474KeepAlive calls runtime.KeepAlive as a

internal/gl/gl_windows.go

@@ -9,8 +9,6 @@ import (
 	"unsafe"
 
 	"golang.org/x/sys/windows"
-
-	gunsafe "gioui.org/internal/unsafe"
 )
 
 var (
@@ -324,7 +322,7 @@ func (c *Functions) GetShaderInfoLog(s Shader) string {
 }
 func (c *Functions) GetString(pname Enum) string {
 	s, _, _ := syscall.Syscall(_glGetString.Addr(), 1, uintptr(pname), 0, 0)
-	return gunsafe.GoString(gunsafe.SliceOf(s))
+	return windows.BytePtrToString((*byte)(unsafe.Pointer(s)))
 }
 func (c *Functions) GetUniformLocation(p Program, name string) Uniform {
 	cname := cString(name)

internal/unsafe/unsafe.go

@@ -44,14 +44,3 @@ func SliceOf(s uintptr) []byte {
 	h.Len = 1 << 30
 	return res
 }
-
-// GoString convert a NUL-terminated C string
-// to a Go string.
-func GoString(s []byte) string {
-	for i, v := range s {
-		if v == 0 {
-			return string(s[:i])
-		}
-	}
-	return string(s)
-}

internal/unsafe/unsafe_test.go

@@ -1,20 +0,0 @@
-// SPDX-License-Identifier: Unlicense OR MIT
-
-package unsafe
-
-import (
-	"testing"
-)
-
-func TestGoString(t *testing.T) {
-	tests := [][2]string{
-		{"Hello\x00", "Hello"},
-		{"\x00", ""},
-	}
-	for _, test := range tests {
-		got := GoString([]byte(test[0]))
-		if exp := test[1]; exp != got {
-			t.Errorf("expected %q got %q", exp, got)
-		}
-	}
-}