[clang] clangCodeGen: Introduce `mcdc::State` with `MCDCState.h` (PR #81497)

[Jessica Paquette via cfe-commits]

================
@@ -0,0 +1,33 @@
+//===---- MCDCState.h - MC/DC-related types for PGO -------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+//  MC/DC-related types for PGO
----------------
ornata wrote:

comment seems misleading; this is only for the per-function MC/DC state, right?

https://github.com/llvm/llvm-project/pull/81497