[LV] Move reportVectorizationInfo to LoopVectorize.cpp (NFC)

The function is only used in LoopVectorize.cpp, no need to define it in
header.

Author: fhahn

llvm/include/llvm/Transforms/Vectorize/LoopVectorize.h

@@ -207,13 +207,6 @@ void reportVectorizationFailure(const StringRef DebugMsg,
     const StringRef OREMsg, const StringRef ORETag,
     OptimizationRemarkEmitter *ORE, Loop *TheLoop, Instruction *I = nullptr);
 
-/// Reports an informative message: print \p Msg for debugging purposes as well
-/// as an optimization remark. Uses either \p I as location of the remark, or
-/// otherwise \p TheLoop.
-void reportVectorizationInfo(const StringRef OREMsg, const StringRef ORETag,
-                             OptimizationRemarkEmitter *ORE, Loop *TheLoop,
-                             Instruction *I = nullptr);
-
 } // end namespace llvm
 
 #endif // LLVM_TRANSFORMS_VECTORIZE_LOOPVECTORIZE_H

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -986,9 +986,12 @@ void reportVectorizationFailure(const StringRef DebugMsg,
       << "loop not vectorized: " << OREMsg);
 }
 
-void reportVectorizationInfo(const StringRef Msg, const StringRef ORETag,
+/// Reports an informative message: print \p Msg for debugging purposes as well
+/// as an optimization remark. Uses either \p I as location of the remark, or
+/// otherwise \p TheLoop.
+static void reportVectorizationInfo(const StringRef Msg, const StringRef ORETag,
                              OptimizationRemarkEmitter *ORE, Loop *TheLoop,
-                             Instruction *I) {
+                             Instruction *I = nullptr) {
   LLVM_DEBUG(debugVectorizationMessage("", Msg, I));
   LoopVectorizeHints Hints(TheLoop, true /* doesn't matter */, *ORE);
   ORE->emit(