Revert "Fix non-capturing closure return type coercion"

Author: workingjubilee

compiler/rustc_typeck/src/check/coercion.rs

@@ -1003,12 +1003,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             exprs.len()
         );
 
-        // The following check fixes #88097, where the compiler erroneously
-        // attempted to coerce a closure type to itself via a function pointer.
-        if prev_ty == new_ty {
-            return Ok(prev_ty);
-        }
-
         // Special-case that coercion alone cannot handle:
         // Function items or non-capturing closures of differing IDs or InternalSubsts.
         let (a_sig, b_sig) = {