Adding upstream version 1.65.7.

Signed-off-by: Daniel Baumann <daniel@debian.org>

libc_all.go

@@ -0,0 +1,53 @@
+// Copyright 2024 The Libc Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package libc is a partial reimplementation of C libc in pure Go.
+package libc // import "modernc.org/libc"
+
+import (
+	"sync/atomic"
+	"unsafe"
+
+	"golang.org/x/exp/constraints"
+)
+
+func X__sync_add_and_fetch[T constraints.Integer](t *TLS, p uintptr, v T) T {
+	switch unsafe.Sizeof(v) {
+	case 4:
+		return T(atomic.AddInt32((*int32)(unsafe.Pointer(p)), int32(v)))
+	case 8:
+		return T(atomic.AddInt64((*int64)(unsafe.Pointer(p)), int64(v)))
+	default:
+		panic(todo(""))
+	}
+}
+
+func X__sync_sub_and_fetch[T constraints.Integer](t *TLS, p uintptr, v T) T {
+	switch unsafe.Sizeof(v) {
+	case 4:
+		return T(atomic.AddInt32((*int32)(unsafe.Pointer(p)), -int32(v)))
+	case 8:
+		return T(atomic.AddInt64((*int64)(unsafe.Pointer(p)), -int64(v)))
+	default:
+		panic(todo(""))
+	}
+}
+
+// GoString returns the value of a C string at s.
+func GoString(s uintptr) string {
+	if s == 0 {
+		return ""
+	}
+
+	p := s
+	for *(*byte)(unsafe.Pointer(p)) != 0 {
+		p++
+	}
+	return string(unsafe.Slice((*byte)(unsafe.Pointer(s)), p-s))
+}
+
+// GoBytes returns a byte slice from a C char* having length len bytes.
+func GoBytes(s uintptr, len int) []byte {
+	return unsafe.Slice((*byte)(unsafe.Pointer(s)), len)
+}