Auto merge of #83839 - ldm0:deref, r=petrochenkov

Remove unneeded type resolving

small optimization.

Author: bors

compiler/rustc_typeck/src/check/expectation.rs

@@ -104,8 +104,8 @@ impl<'a, 'tcx> Expectation<'tcx> {
     /// for the program to type-check). `only_has_type` will return
     /// such a constraint, if it exists.
     pub(super) fn only_has_type(self, fcx: &FnCtxt<'a, 'tcx>) -> Option<Ty<'tcx>> {
-        match self.resolve(fcx) {
-            ExpectHasType(ty) => Some(ty),
+        match self {
+            ExpectHasType(ty) => Some(fcx.resolve_vars_if_possible(ty)),
             NoExpectation | ExpectCastableToType(_) | ExpectRvalueLikeUnsized(_) | IsLast(_) => {
                 None
             }

compiler/rustc_typeck/src/check/expr.rs

@@ -161,7 +161,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expr: &'tcx hir::Expr<'tcx>,
         expected: Expectation<'tcx>,
     ) -> Ty<'tcx> {
-        debug!(">> type-checking: expr={:?} expected={:?}", expr, expected);
+        debug!(">> type-checking: expected={:?}, expr={:?} ", expected, expr);
 
         // True if `expr` is a `Try::from_ok(())` that is a result of desugaring a try block
         // without the final expr (e.g. `try { return; }`). We don't want to generate an
@@ -224,7 +224,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expr: &'tcx hir::Expr<'tcx>,
         expected: Expectation<'tcx>,
     ) -> Ty<'tcx> {
-        debug!("check_expr_kind(expr={:?}, expected={:?})", expr, expected);
+        debug!("check_expr_kind(expected={:?}, expr={:?})", expected, expr);
 
         let tcx = self.tcx;
         match expr.kind {