[Diagnostics] Adjust to get expr from type node anchor

Author: LucianoPAlmeida

lib/Sema/CSDiagnostics.cpp

@@ -5547,7 +5547,7 @@ bool ThrowingFunctionConversionFailure::diagnoseAsError() {
 }
 
 bool UnnecessaryCoercionFailure::diagnoseAsError() {
-  auto expr = cast<CoerceExpr>(getAnchor());
+  auto expr = getAsExpr<CoerceExpr>(getAnchor());
   auto sourceRange =
       SourceRange(expr->getLoc(), expr->getCastTypeLoc().getSourceRange().End);
   auto castType = expr->getCastTypeLoc().getType();
@@ -5558,15 +5558,14 @@ bool UnnecessaryCoercionFailure::diagnoseAsError() {
     auto toTypeAlias = cast<TypeAliasType>(getToType().getPointer());
     // If the typealias are different, we need a warning mentioning both types.
     if (fromTypeAlias->getDecl() != toTypeAlias->getDecl()) {
-      emitDiagnostic(expr->getLoc(),
-                     diag::unnecessary_same_typealias_type_coercion,
+      emitDiagnostic(diag::unnecessary_same_typealias_type_coercion,
                      getFromType(), castType)
           .fixItRemove(sourceRange);
       return true;
     }
   }
 
-  emitDiagnostic(expr->getLoc(), diag::unnecessary_same_type_coercion,
+  emitDiagnostic(diag::unnecessary_same_type_coercion,
                  castType)
       .fixItRemove(sourceRange);
   return true;

lib/Sema/CSFix.cpp

@@ -1155,7 +1155,7 @@ bool RemoveUnnecessaryCoercion::attempt(ConstraintSystem &cs, Type fromType,
   if (!isExplicitCoercion)
     return false;
 
-  auto expr = cast<CoerceExpr>(locator.getAnchor());
+  auto expr = getAsExpr<CoerceExpr>(locator.getAnchor());
 
   // Check to ensure the from and to types are equal the cast type.
   // This is required to handle cases where the conversion is done

lib/Sema/CSSimplify.cpp

@@ -10510,7 +10510,7 @@ void ConstraintSystem::addExplicitConversionConstraint(
   auto locatorPtr = getConstraintLocator(locator);
   ConstraintLocator *coerceLocator = locatorPtr;
 
-  auto *anchor = locator.getAnchor();
+  auto *anchor = getAsExpr(locator.getAnchor());
   if (anchor && isa<CoerceExpr>(anchor) && !anchor->isImplicit()) {
     coerceLocator =
         getConstraintLocator(anchor, LocatorPathElt::ExplicitTypeCoercion());