Enable the -Wextra compiler flag in the wren.mk build configuration, which was previously commented out with a TODO. To handle the new unused parameter warnings triggered by -Wextra (particularly for WrenVM* vm parameters in several functions), add -Wno-unused-parameter to suppress them. Also fix a declaration ordering issue in wren_vm.c where the 'static' keyword was placed after the return type in loadIntoCore, moving it to the correct position before the type specifier.