LibJS: Expose various offsets for GetGlobal JIT fast path

Author: https://github.com/iliadsh
Commit: ddea710933
Pull-request: https://github.com/SerenityOS/serenity/pull/21919

Userland/Libraries/LibJS/Runtime/ObjectEnvironment.h

@@ -41,6 +41,8 @@ public:
     // [[IsWithEnvironment]], Indicates whether this Environment Record is created for a with statement.
     bool is_with_environment() const { return m_with_environment; }
 
+    static FlatPtr binding_object_offset() { return OFFSET_OF(ObjectEnvironment, m_binding_object); }
+
 private:
     ObjectEnvironment(Object& binding_object, IsWithEnvironment, Environment* outer_environment);