all: remove unnecessary copying

Copying []byte to string should copy the data if necessary, as the
Go specification assures that strings are immutable.

internal/cocoa/api_cocoa_darwin.go

@@ -280,13 +280,7 @@ func (s NSString) InitWithUTF8String(utf8 string) NSString {
 }
 
 func (s NSString) String() string {
-	// The lifetime of the underlying C string is shorter than s [1].
-	// Copy the bytes to ensure that the returned string's lifetime is unrelated to s.
-	// [1] https://developer.apple.com/documentation/foundation/nsstring/1411189-utf8string?language=objc
-	src := unsafe.Slice((*byte)(unsafe.Pointer(s.Send(sel_UTF8String))), s.Send(sel_length))
-	dst := make([]byte, len(src))
-	copy(dst, src)
-	return string(dst)
+	return string(unsafe.Slice((*byte)(unsafe.Pointer(s.Send(sel_UTF8String))), s.Send(sel_length)))
 }
 
 type NSNotification struct {

internal/graphicsdriver/directx/api_windows.go

@@ -2293,9 +2293,7 @@ func (i *_ID3DBlob) Release() uint32 {
 }
 
 func (i *_ID3DBlob) String() string {
-	bs := make([]byte, int(i.GetBufferSize()))
-	copy(bs, unsafe.Slice((*byte)(unsafe.Pointer(i.GetBufferPointer())), i.GetBufferSize()))
-	return string(bs)
+	return string(unsafe.Slice((*byte)(unsafe.Pointer(i.GetBufferPointer())), i.GetBufferSize()))
 }
 
 type _IDXGIAdapter struct {

internal/graphicsdriver/opengl/gl/conversions_nocgo.go

@@ -18,9 +18,7 @@ func GoStr(cstr *byte) string {
 	x := unsafe.Slice(cstr, 1e9)
 	for i, c := range x {
 		if c == 0 {
-			str := make([]byte, i)
-			copy(str, x[:i])
-			return string(str)
+			return string(x[:i])
 		}
 	}
 	return ""