Remove Flow workaround for const arguments (#1848)

src/type/directives.js

@@ -190,10 +190,6 @@ export const specifiedDirectives: $ReadOnlyArray<*> = [
 export function isSpecifiedDirective(directive: mixed): boolean %checks {
   return (
     isDirective(directive) &&
-    // Would prefer to use specifiedDirectives.some(), however %checks needs
-    // a simple expression.
-    (directive.name === GraphQLIncludeDirective.name ||
-      directive.name === GraphQLSkipDirective.name ||
-      directive.name === GraphQLDeprecatedDirective.name)
+    specifiedDirectives.some(({ name }) => name === directive.name)
   );
 }

src/type/introspection.js

@@ -487,15 +487,6 @@ export const introspectionTypes: $ReadOnlyArray<*> = [
 export function isIntrospectionType(type: mixed): boolean %checks {
   return (
     isNamedType(type) &&
-    // Would prefer to use introspectionTypes.some(), however %checks needs
-    // a simple expression.
-    (type.name === __Schema.name ||
-      type.name === __Directive.name ||
-      type.name === __DirectiveLocation.name ||
-      type.name === __Type.name ||
-      type.name === __Field.name ||
-      type.name === __InputValue.name ||
-      type.name === __EnumValue.name ||
-      type.name === __TypeKind.name)
+    introspectionTypes.some(({ name }) => type.name === name)
   );
 }

src/type/scalars.js

@@ -256,12 +256,6 @@ export const specifiedScalarTypes: $ReadOnlyArray<*> = [
 export function isSpecifiedScalarType(type: mixed): boolean %checks {
   return (
     isScalarType(type) &&
-    // Would prefer to use specifiedScalarTypes.some(), however %checks needs
-    // a simple expression.
-    (type.name === GraphQLString.name ||
-      type.name === GraphQLInt.name ||
-      type.name === GraphQLFloat.name ||
-      type.name === GraphQLBoolean.name ||
-      type.name === GraphQLID.name)
+    specifiedScalarTypes.some(({ name }) => type.name === name)
   );
 }