fix(validate): use referential equality check for type objects

Author: thomasheyenbrock

src/type/validate.ts

@@ -145,7 +145,7 @@ function validateRootTypes(context: SchemaValidationContext): void {
     );
   }
 
-  if (queryType && mutationType && queryType.name === mutationType.name) {
+  if (queryType && mutationType && queryType === mutationType) {
     context.reportError(
       'All root types must be different, ' +
         queryType.name +
@@ -155,11 +155,7 @@ function validateRootTypes(context: SchemaValidationContext): void {
     );
   }
 
-  if (
-    queryType &&
-    subscriptionType &&
-    queryType.name === subscriptionType.name
-  ) {
+  if (queryType && subscriptionType && queryType === subscriptionType) {
     context.reportError(
       'All root types must be different, ' +
         queryType.name +
@@ -169,11 +165,7 @@ function validateRootTypes(context: SchemaValidationContext): void {
     );
   }
 
-  if (
-    mutationType &&
-    subscriptionType &&
-    mutationType.name === subscriptionType.name
-  ) {
+  if (mutationType && subscriptionType && mutationType === subscriptionType) {
     context.reportError(
       'All root types must be different, ' +
         mutationType.name +