[clang] [flang] [flang][flang-driver] Support flag -finstrument-functions (PR #137996)

[Tarun Prabhu via cfe-commits]

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@@ -124,6 +128,8 @@ struct MLIRToLLVMPassPipelineConfig : public FlangEPCallBacks {
   bool UnsafeFPMath = false; ///< Set unsafe-fp-math attribute for functions.
   bool NSWOnLoopVarInc = true; ///< Add nsw flag to loop variable increments.
   bool EnableOpenMP = false; ///< Enable OpenMP lowering.
+  std::string InstrumentFunctionsEntry = "";
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tarunprabhu wrote:

Might help to add a brief comment clarifying that these are the names of the functions that will be called on entry and exit of an instrumented function

https://github.com/llvm/llvm-project/pull/137996