lib.builder: '}' doesn't pop the origin stack

[doug-moen]

lib.builder is buggy and the behaviour does not match the documentation.

Specifically, the '{' operator pushes the current origin onto a stack.
The '}' operator contains code whose apparent intent is to pop the previously pushed origin,
and restore the origin to what it was when '{' was called.
But the code is buggy, and it doesn't actually do that. The stack isn't popped, and the current
origin doesn't change.

The only thing that '}' actually does is set the origin_prev field to the current origin.
And that has no effect if the next operation is '*'.
It only has an effect if the very next operation is '{'.

Assigned to: @lf94

[lf94]

Thanks @doug-moen , I'll open a PR tonight. ☺