Remove old FIXME that no longer applies

fee1-dead · fee1-dead · commit 255eb217e9f5 · 2023-02-20T06:26:28.000Z
it looks like Encodable was fallible at some point, but that was changed
which means that this FIXME is no longer applicable
diff --git a/compiler/rustc_serialize/src/serialize.rs b/compiler/rustc_serialize/src/serialize.rs
@@ -430,11 +430,6 @@ impl<D: Decoder, T: Decodable<D> + Copy> Decodable<D> for Cell<T> {
     }
 }
 
-// FIXME: #15036
-// Should use `try_borrow`, returning an
-// `encoder.error("attempting to Encode borrowed RefCell")`
-// from `encode` when `try_borrow` returns `None`.
-
 impl<S: Encoder, T: Encodable<S>> Encodable<S> for RefCell<T> {
     fn encode(&self, s: &mut S) {
         self.borrow().encode(s);

Original file line number	Diff line number	Diff line change
`@@ -430,11 +430,6 @@ impl<D: Decoder, T: Decodable<D> + Copy> Decodable<D> for Cell<T> {`
`430`	`430`	`}`
`431`	`431`	`}`
`432`	`432`
`433`		`-// FIXME: #15036`
`434`		-// Should use `try_borrow`, returning an
`435`		-// `encoder.error("attempting to Encode borrowed RefCell")`
`436`		-// from `encode` when `try_borrow` returns `None`.
`437`		`-`
`438`	`433`	`impl<S: Encoder, T: Encodable<S>> Encodable<S> for RefCell<T> {`
`439`	`434`	`fn encode(&self, s: &mut S) {`
`440`	`435`	`self.borrow().encode(s);`