types created inside functions are named after the function

[andrewrk]

This is useful for e.g.

pub fn ArrayList(comptime T: type) -> type {
    return struct {
        ...
    };
}

because now the type name created by ArrayList(u8) is ArrayList(u8).

however it becomes more problematic in this case:

export fn entry() {
    const Foo = struct { x: i32 };

    @compileLog(@typeName(Foo));
}

This prints entry() as the name of the Foo type, which is incorrect.

I think inside a function, if you assign an anonymous struct to a variable, we can use the variable name as the type name.