[clang] [CIR][CodeGen] Upstream support for FP environments and RAII options (PR #179121)

[Andy Kaylor via cfe-commits]

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@@ -0,0 +1,50 @@
+//===- FPEnv.h ---- FP Environment ------------------------------*- 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
+//
+//===----------------------------------------------------------------------===//
+//
+/// @file
+/// This file contains the declarations of entities that describe floating
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andykaylor wrote:

Why can't we use these definitions directly from `llvm/include/llvm/IR/FPEnv.h` instead of recreating them for CIR?

https://github.com/llvm/llvm-project/pull/179121