Support: Add operator== for MemoryBufferRef and split out MemoryBufferRef.h

As preparation for changing `LineIterator` to work with `MemoryBufferRef`:

- Add an `operator==` that uses buffer pointer identity to ensure two buffers
  are equivalent.
- Split out `MemoryBufferRef.h`, to avoid polluting `LineIterator.h` includers
  with everything from `MemoryBuffer.h`. This also means moving the
  `MemoryBuffer` constructor to a source file.

Differential Revision: https://reviews.llvm.org/D89279

1 files changed, 19 insertions, 0 deletions

diff --git a/llvm/lib/Support/MemoryBufferRef.cpp b/llvm/lib/Support/MemoryBufferRef.cpp
new file mode 100644
index 0000000..a93853c
--- /dev/null
+++ b/llvm/lib/Support/MemoryBufferRef.cpp
@@ -0,0 +1,19 @@
+//===- MemoryBufferRef.cpp - Memory Buffer Reference ----------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements the MemoryBufferRef interface.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/MemoryBufferRef.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+using namespace llvm;
+
+MemoryBufferRef::MemoryBufferRef(const MemoryBuffer &Buffer)
+    : Buffer(Buffer.getBuffer()), Identifier(Buffer.getBufferIdentifier()) {}