setInitializer

        pub fn setInitializer(
            self: Index,
            initializer: Constant,
            builder: *Builder,
        ) Allocator.Error!void {
            if (initializer != .no_init) {
                const variable = self.ptrConst(builder);
                const global = variable.global.ptr(builder);
                const initializer_type = initializer.typeOf(builder);
                global.type = initializer_type;
            }
            self.ptr(builder).init = initializer;
        }