Move object literal checking into checker classes

src/x64/full-codegen-x64.cc

Index: src/x64/full-codegen-x64.cc
diff --git a/src/x64/full-codegen-x64.cc b/src/x64/full-codegen-x64.cc
index a8d20beb1e2dd7f8ac1c14797168b66ed46fc8f8..28082bc55d5993251eba4d526cfabe0de0cf36b0 100644
--- a/src/x64/full-codegen-x64.cc
+++ b/src/x64/full-codegen-x64.cc
@@ -1707,11 +1707,8 @@ void FullCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
       case ObjectLiteral::Property::PROTOTYPE:
         __ Push(Operand(rsp, 0));  // Duplicate receiver.
         VisitForStackValue(value);
-        if (property->emit_store()) {
-          __ CallRuntime(Runtime::kInternalSetPrototype, 2);
-        } else {
-          __ Drop(2);
-        }
+        DCHECK(property->emit_store());
+        __ CallRuntime(Runtime::kInternalSetPrototype, 2);
         break;
       case ObjectLiteral::Property::GETTER:
         accessor_table.lookup(key)->second->getter = value;
@@ -1760,11 +1757,8 @@ void FullCodeGenerator::VisitObjectLiteral(ObjectLiteral* expr) {
     if (property->kind() == ObjectLiteral::Property::PROTOTYPE) {
       DCHECK(!property->is_computed_name());
       VisitForStackValue(value);
-      if (property->emit_store()) {
-        __ CallRuntime(Runtime::kInternalSetPrototype, 2);
-      } else {
-        __ Drop(2);
-      }
+      DCHECK(property->emit_store());
+      __ CallRuntime(Runtime::kInternalSetPrototype, 2);
     } else {
       EmitPropertyKey(property);
       VisitForStackValue(value);
@@ -2468,8 +2462,9 @@ void FullCodeGenerator::EmitClassDefineProperties(ClassLiteral* lit) {
     switch (property->kind()) {
       case ObjectLiteral::Property::CONSTANT:
       case ObjectLiteral::Property::MATERIALIZED_LITERAL:
-      case ObjectLiteral::Property::COMPUTED:
       case ObjectLiteral::Property::PROTOTYPE:
+        UNREACHABLE();
+      case ObjectLiteral::Property::COMPUTED:
         __ CallRuntime(Runtime::kDefineClassMethod, 3);
         break;