LibJS/Bytecode: Always make own properties in object expressions

When building an object from an object expression, we don't want to
go through the full property setting machinery. This patch adds a new
PropertyKind::DirectKeyValue for PutById which guarantees that the
property becomes an own property.

This fixes an issue where setting the "__proto__" property in object
expressions wasn't working right.

12 new passes on test262. :^)

Userland/Libraries/LibJS/Bytecode/Op.h

@@ -644,6 +644,7 @@ enum class PropertyKind {
     Getter,
     Setter,
     KeyValue,
+    DirectKeyValue, // Used for Object expressions. Always sets an own property, never calls a setter.
     Spread,
     ProtoSetter,
 };