Add optional heritage for classes syntax templates

src/class-elements/syntax/invalid/cls-decl-elements-invalid-syntax.template

@@ -13,6 +13,6 @@ negative:
 
 throw "Test262: This statement should not be evaluated.";
 
-class C {
+class C /*{ heritage }*/ {
   /*{ elements }*/
 }

src/class-elements/syntax/invalid/cls-expr-elements-invalid-syntax.template

@@ -13,6 +13,6 @@ negative:
 
 throw "Test262: This statement should not be evaluated.";
 
-var C = class {
+var C = class /*{ heritage }*/ {
   /*{ elements }*/
 };

src/class-elements/syntax/valid/cls-decl-elements-valid-syntax.template

@@ -8,6 +8,6 @@ path: language/statements/class/syntax/valid/
 features: [class]
 ---*/
 
-class C {
+class C /*{ heritage }*/ {
   /*{ elements }*/
 }

src/class-elements/syntax/valid/cls-expr-elements-valid-syntax.template

@@ -8,6 +8,6 @@ path: language/expressions/class/syntax/valid/
 features: [class]
 ---*/
 
-var C = class {
+var C = class /*{ heritage }*/ {
   /*{ elements }*/
 };