[Diagnostic] Fix regression in requirement diagnostics

Author: LucianoPAlmeida

lib/Sema/CSDiagnostics.cpp

@@ -282,6 +282,9 @@ ValueDecl *RequirementFailure::getDeclRef() const {
     return getAffectedDeclFromType(contextualTy);
   }
 
+  if (getLocator()->isFirstElement<LocatorPathElt::CoercionOperand>())
+    return getAffectedDeclFromType(getOwnerType());
+
   if (auto overload = getCalleeOverloadChoiceIfAvailable(getLocator())) {
     // If there is a declaration associated with this
     // failure e.g. an overload choice of the call

lib/Sema/CSGen.cpp

@@ -3329,9 +3329,8 @@ namespace {
       // bindings for the result of the coercion.
       if (repr &&
           repr->getKind() == TypeReprKind::ImplicitlyUnwrappedOptional) {
-        auto *locatorIUO = CS.getConstraintLocator(expr);
-        return createTypeVariableAndDisjunctionForIUOCoercion(toType,
-                                                              locatorIUO);
+        return createTypeVariableAndDisjunctionForIUOCoercion(
+            toType, CS.getConstraintLocator(expr));
       }
 
       return toType;