metadata is not forwarded to bound symbols in `p/let`

[lilactown]

I have in a ClojureScript project something akin to:

(ns app.foo
  (:require
    [promesa.core :as p]))

(deftype Foo [bar baz])

(defn foo
  [bar baz]
  (->Foo bar baz))

(p/let [x (foo "bar" "baz")]
  (set! (.-bar foo) "qux")))

shadow-cljs compiles the code with a warning "Cannot infer target type in expression: (set! (.-bar foo) "qux")". Changing the code to use let instead of p/let fixes the issue.

I believe (via our Slack thread) that this is because x does not get the correct metadata attached to it when p/let is constructing the bindings.

[niwinz]

I have revisited this several times, but metadata is forwarded on bindings so i don't know how to properly solve that...