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;
}