Fix layering violation

Suggested at
<llvm#148758 (comment)>.

Author: jdenny-ornl

llvm/include/llvm/IR/ProfDataUtils.h

@@ -30,6 +30,10 @@ struct MDProfLabels {
   LLVM_ABI static const char *UnknownBranchWeightsMarker;
 };
 
+/// Profile-based loop metadata that should be accessed only by using
+/// \c llvm::getLoopEstimatedTripCount and \c llvm::setLoopEstimatedTripCount.
+LLVM_ABI extern const char *LLVMLoopEstimatedTripCount;
+
 /// Checks if an Instruction has MD_prof Metadata
 LLVM_ABI bool hasProfMD(const Instruction &I);
 

llvm/include/llvm/Transforms/Utils/LoopUtils.h

@@ -52,8 +52,6 @@ typedef std::pair<const RuntimeCheckingPtrGroup *,
 template <typename T, unsigned N> class SmallSetVector;
 template <typename T, unsigned N> class SmallPriorityWorklist;
 
-const char *const LLVMLoopEstimatedTripCount = "llvm.loop.estimated_trip_count";
-
 LLVM_ABI BasicBlock *InsertPreheaderForLoop(Loop *L, DominatorTree *DT,
                                             LoopInfo *LI,
                                             MemorySSAUpdater *MSSAU,

llvm/lib/IR/ProfDataUtils.cpp

@@ -95,6 +95,7 @@ const char *MDProfLabels::FunctionEntryCount = "function_entry_count";
 const char *MDProfLabels::SyntheticFunctionEntryCount =
     "synthetic_function_entry_count";
 const char *MDProfLabels::UnknownBranchWeightsMarker = "unknown";
+const char *LLVMLoopEstimatedTripCount = "llvm.loop.estimated_trip_count";
 
 bool hasProfMD(const Instruction &I) {
   return I.hasMetadata(LLVMContext::MD_prof);

llvm/lib/IR/Verifier.cpp

@@ -121,7 +121,6 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/ModRef.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/Transforms/Utils/LoopUtils.h"
 #include <algorithm>
 #include <cassert>
 #include <cstdint>