Introduce libc wrappers like v8::base::Malloc

The Cobalt project has its own Starboard equivalent of libc APIs like
`malloc` and `free`. This CL introduces the wrappers for some libc
functions. In followup CLs, for example occurences of malloc will all
be replaced by base::Malloc in V8.

See b/156155426 for more information.

Bug: v8:10927
Change-Id: Ida3d161a1da56755b681e18b4827e277e6cb4c4d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2416150
Commit-Queue: John Xu <johnx@google.com>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Auto-Submit: John Xu <johnx@google.com>
Cr-Commit-Position: refs/heads/master@{#70702}

BUILD.gn

@@ -4071,6 +4071,8 @@ v8_component("v8_libbase") {
     "src/base/platform/semaphore.h",
     "src/base/platform/time.cc",
     "src/base/platform/time.h",
+    "src/base/platform/wrappers.h",
+    "src/base/platform/wrappers_std.cc",
     "src/base/region-allocator.cc",
     "src/base/region-allocator.h",
     "src/base/ring-buffer.h",

src/base/platform/wrappers.h

+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef V8_BASE_PLATFORM_WRAPPERS_H_
+#define V8_BASE_PLATFORM_WRAPPERS_H_
+
+#include <stddef.h>
+#include <stdio.h>
+
+namespace v8 {
+namespace base {
+
+void* Malloc(size_t size);
+
+void* Realloc(void* memory, size_t size);
+
+void Free(void* memory);
+
+void* Calloc(size_t count, size_t size);
+
+void* Memcpy(void* dest, const void* source, size_t count);
+
+FILE* Fopen(const char* filename, const char* mode);
+
+int Fclose(FILE* stream);
+
+}  // namespace base
+}  // namespace v8
+
+#endif  // V8_BASE_PLATFORM_WRAPPERS_H_

src/base/platform/wrappers_starboard.cc

+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "starboard/memory.h"
+
+#include "src/base/platform/wrappers.h"
+
+namespace v8 {
+namespace base {
+
+void* Malloc(size_t size) { return SbMemoryAlloc(size); }
+
+void* Realloc(void* memory, size_t size) {
+  return SbMemoryReallocate(memory, size);
+}
+
+void Free(void* memory) { return SbMemoryDeallocate(memory); }
+
+void* Calloc(size_t count, size_t size) { return SbMemoryCalloc(count, size); }
+
+void* Memcpy(void* dest, const void* source, size_t count) {
+  return SbMemoryCopy(dest, source, count);
+}
+
+FILE* Fopen(const char* filename, const char* mode) { return NULL; }
+
+int Fclose(FILE* stream) { return -1; }
+
+}  // namespace base
+}  // namespace v8

src/base/platform/wrappers_std.cc

+// Copyright 2020 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "src/base/platform/wrappers.h"
+
+namespace v8 {
+namespace base {
+
+void* Malloc(size_t size) { return malloc(size); }
+
+void* Realloc(void* memory, size_t size) { return realloc(memory, size); }
+
+void Free(void* memory) { return free(memory); }
+
+void* Calloc(size_t count, size_t size) { return calloc(count, size); }
+
+void* Memcpy(void* dest, const void* source, size_t count) {
+  return memcpy(dest, source, count);
+}
+
+FILE* Fopen(const char* filename, const char* mode) {
+  return fopen(filename, mode);
+}
+
+int Fclose(FILE* stream) { return fclose(stream); }
+
+}  // namespace base
+}  // namespace v8