[clang] [clang][ssaf] Introduce entity abstraction for SSAF (PR #169131)

[Yitzhak Mandelbaum via cfe-commits]

================
@@ -0,0 +1,47 @@
+//===- EntityName.h ---------------------------------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_ANALYSIS_SCALABLE_ENTITY_NAME_H
+#define LLVM_CLANG_ANALYSIS_SCALABLE_ENTITY_NAME_H
+
+#include "clang/Analysis/Scalable/Model/BuildNamespace.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
+#include <string>
+
+namespace clang {
+namespace ssaf {
+
+/// Uniquely identifies an entity in a program.
+///
+/// EntityName provides a globally unique identifier for program entities that remains
+/// stable across compilation boundaries. This enables whole-program analysis to track
+/// and relate entities across separately compiled translation units.
+class EntityName {
----------------
ymand wrote:

nit: Consider `EntityID` -- its shorter and (IMO) more intuitive. I think of "name" more for circumstances where the identifier is readable. But, it's a matter of taste. 

https://github.com/llvm/llvm-project/pull/169131