Remove --experimental-classes flag and related dead code.

src/ppc/full-codegen-ppc.cc

Index: src/ppc/full-codegen-ppc.cc
diff --git a/src/ppc/full-codegen-ppc.cc b/src/ppc/full-codegen-ppc.cc
index 39f0ed918b472005bdbff8cc148083c2e578ab47..69bcc05749f1dcb8d311f945760f4db5cdb55f75 100644
--- a/src/ppc/full-codegen-ppc.cc
+++ b/src/ppc/full-codegen-ppc.cc
@@ -3169,15 +3169,7 @@ void FullCodeGenerator::VisitCall(Call* expr) {
       }
     }
   } else if (call_type == Call::SUPER_CALL) {
-    if (FLAG_experimental_classes) {
-      EmitSuperConstructorCall(expr);
-    } else {
-      SuperReference* super_ref = callee->AsSuperReference();
-      EmitLoadSuperConstructor(super_ref);
-      __ Push(result_register());
-      VisitForStackValue(super_ref->this_var());
-      EmitCall(expr, CallICState::METHOD);
-    }
+    EmitSuperConstructorCall(expr);
   } else {
     DCHECK(call_type == Call::OTHER_CALL);
     // Call to an arbitrary expression not handled specially above.