[llvm] [CodeGen][NewPM] Extract MachineFunctionProperties modification part to an RAII class (PR #94854)

[Arthur Eubanks via llvm-commits]

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@@ -245,24 +245,27 @@ class PassManager : public PassInfoMixin<
     return PA;
   }
 
-  // FIXME: Revert to enable_if style when gcc >= 11.1
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aeubanks wrote:

https://www.llvm.org/docs/GettingStarted.html#getting-a-modern-host-c-toolchain says we still support some gcc <11 (this should be a separate PR anyway)

https://github.com/llvm/llvm-project/pull/94854