[wpiutil] Vendor llvm and update to 13.0.0 (#4224)

wpiutil/src/main/native/cpp/llvm/MemAlloc.cpp

@@ -0,0 +1,34 @@
+//===- MemAlloc.cpp - Memory allocation functions -------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "wpi/MemAlloc.h"
+
+// These are out of line to have __cpp_aligned_new not affect ABI.
+
+LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void *
+wpi::allocate_buffer(size_t Size, size_t Alignment) {
+  return ::operator new(Size
+#ifdef __cpp_aligned_new
+                        ,
+                        std::align_val_t(Alignment)
+#endif
+  );
+}
+
+void wpi::deallocate_buffer(void *Ptr, size_t Size, size_t Alignment) {
+  ::operator delete(Ptr
+#ifdef __cpp_sized_deallocation
+                    ,
+                    Size
+#endif
+#ifdef __cpp_aligned_new
+                    ,
+                    std::align_val_t(Alignment)
+#endif
+  );
+}