slowdown in resolve

The following is causing a pretty bad slowdown:

(function foo() {
    (function foo() {
        (function foo() {
            (function foo() {
                (function foo() {
                    (function foo() {
                        (function foo() {
                            (function foo() {
                                (function foo() {
                                    (function foo() {


                                    })
                                })
                            })
                        })
                    })
                })
            })
        })
    })
})

Same thing happens to nested macro definitions and identical vars being generated from a macro:

macro m {
    case {_ () } => { return #{var x;} }
}
m ()
m ()
m ()
m ()
...

The slowdown is taking place in resolve. Pretty sure this has to do with how we handle definition contexts.