[llvm] [llvm][ctx_profile] Add instrumentation (PR #90136)

[Teresa Johnson via llvm-commits]

================
@@ -0,0 +1,19 @@
+//===- PGOCtxProfLowering.cpp - Contextual PGO Instr. Lowering ------------===//
+//
+// 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 "llvm/Transforms/Instrumentation/PGOCtxProfLowering.h"
+#include "llvm/Support/CommandLine.h"
+
+using namespace llvm;
+
+static cl::list<std::string> ContextRoots("profile-context-root");
----------------
teresajohnson wrote:

Also, it doesn't seem as though this is used now, other than to say whether contextual profiling is enabled. Is that expected?

https://github.com/llvm/llvm-project/pull/90136