More . completion

[llogick]

Goal was

// inside "MyStruct.zig"
a: bool,
b: bool,

// inside "main.zig"
const MyStruct = @import("MyStruct.zig");

fn topLevelStruct() void {
    var s = MyStruct{.<completion>};
}

but also

const MyStruct = @import("myfile.zig").MyStruct;

fn topLevelStruct() void {
    var s = MyStruct{.<completion>};
}

which hinged on