Fix ICE

Author: sjwang05

compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs

@@ -2112,7 +2112,8 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             && !expected_inputs.is_empty()
             && expected_inputs.len() == found_inputs.len()
             && let Some(typeck) = &self.typeck_results
-            && let Res::Def(_, fn_def_id) = typeck.qpath_res(&path, *arg_hir_id)
+            && let Res::Def(res_kind, fn_def_id) = typeck.qpath_res(&path, *arg_hir_id)
+            && res_kind.is_fn_like()
         {
             let closure: Vec<_> = self
                 .tcx

tests/ui/mismatched_types/issue-118510.rs

@@ -0,0 +1,13 @@
+pub enum Sexpr<'a> {
+    Ident(&'a mut S),
+    //~^ ERROR cannot find type `S` in this scope [E0412]
+}
+
+fn map<'a, F: FnOnce(&Foo<'a>) -> T>(f: F) {}
+//~^ ERROR cannot find type `Foo` in this scope [E0412]
+//~| ERROR cannot find type `T` in this scope [E0412]
+
+fn main() {
+    map(Sexpr::Ident);
+    //~^ ERROR type mismatch in function arguments
+}

tests/ui/mismatched_types/issue-118510.stderr

@@ -0,0 +1,52 @@
+error[E0412]: cannot find type `S` in this scope
+  --> $DIR/issue-118510.rs:2:19
+   |
+LL |     Ident(&'a mut S),
+   |                   ^ not found in this scope
+   |
+help: you might be missing a type parameter
+   |
+LL | pub enum Sexpr<'a, S> {
+   |                  +++
+
+error[E0412]: cannot find type `Foo` in this scope
+  --> $DIR/issue-118510.rs:6:23
+   |
+LL | fn map<'a, F: FnOnce(&Foo<'a>) -> T>(f: F) {}
+   |                       ^^^ not found in this scope
+
+error[E0412]: cannot find type `T` in this scope
+  --> $DIR/issue-118510.rs:6:35
+   |
+LL | fn map<'a, F: FnOnce(&Foo<'a>) -> T>(f: F) {}
+   |            -                      ^ help: a type parameter with a similar name exists: `F`
+   |            |
+   |            similarly named type parameter `F` defined here
+
+error[E0631]: type mismatch in function arguments
+  --> $DIR/issue-118510.rs:11:9
+   |
+LL |     Ident(&'a mut S),
+   |     ----- found signature defined here
+...
+LL |     map(Sexpr::Ident);
+   |     --- ^^^^^^^^^^^^ expected due to this
+   |     |
+   |     required by a bound introduced by this call
+   |
+   = note: expected function signature `for<'a> fn(&'a {type error}) -> _`
+              found function signature `fn(&mut {type error}) -> _`
+note: required by a bound in `map`
+  --> $DIR/issue-118510.rs:6:15
+   |
+LL | fn map<'a, F: FnOnce(&Foo<'a>) -> T>(f: F) {}
+   |               ^^^^^^^^^^^^^^^^^^^^^ required by this bound in `map`
+help: consider wrapping the function in a closure
+   |
+LL |     map(|arg0: &{type error}| Sexpr::Ident(&mut *arg0));
+   |         +++++++++++++++++++++             ++++++++++++
+
+error: aborting due to 4 previous errors
+
+Some errors have detailed explanations: E0412, E0631.
+For more information about an error, try `rustc --explain E0412`.