[mv-func-addr-check] Refactor unsupported move diagnostics into helper function.

I want to over time expand this and improve QoI by adding better error messages
by using pattern matching here. So it makes sense just to take care of the
refactoring now before making further changes.

Author: gottesmm

lib/SILOptimizer/Mandatory/MoveKillsCopyableValuesChecker.cpp

@@ -419,6 +419,18 @@ bool MoveKillsCopyableValuesChecker::check() {
   return false;
 }
 
+//===----------------------------------------------------------------------===//
+//                        Unsupported Use Case Errors
+//===----------------------------------------------------------------------===//
+
+static void emitUnsupportedUseCaseError(MoveValueInst *mvi) {
+  auto &astContext = mvi->getModule().getASTContext();
+  auto diag = diag::
+    sil_movekillscopyablevalue_move_applied_to_unsupported_move;
+  diagnose(astContext, mvi->getLoc().getSourceLoc(), diag);
+  mvi->setAllowsDiagnostics(false);
+}
+
 //===----------------------------------------------------------------------===//
 //                            Top Level Entrypoint
 //===----------------------------------------------------------------------===//
@@ -455,10 +467,7 @@ class MoveKillsCopyableValuesCheckerPass : public SILFunctionTransform {
       for (auto &inst : block) {
         if (auto *mvi = dyn_cast<MoveValueInst>(&inst)) {
           if (mvi->getAllowDiagnostics()) {
-            auto diag = diag::
-                sil_movekillscopyablevalue_move_applied_to_unsupported_move;
-            diagnose(astContext, mvi->getLoc().getSourceLoc(), diag);
-            mvi->setAllowsDiagnostics(false);
+            emitUnsupportedUseCaseError(mvi);
           }
         }
       }