c++: Fix deferred noexcept on constructor [PR93901].

My change in r10-4394 to only update clones when we actually instantiate a
deferred noexcept-spec broke this because deferred parsing updates the
primary function but not the clones.  For GCC 10, let's just revert it.

gcc/cp/ChangeLog
2020-03-10  Jason Merrill  <jason@redhat.com>

	PR c++/93901
	* pt.c (maybe_instantiate_noexcept): Always update clones.

gcc/cp/ChangeLog

 2020-03-10  Jason Merrill  <jason@redhat.com>
 
+	PR c++/93901
+	* pt.c (maybe_instantiate_noexcept): Always update clones.
+
+2020-03-10  Jason Merrill  <jason@redhat.com>
+
 	PR c++/93956
 	* pt.c (maybe_aggr_guide): Check BRACE_ENCLOSED_INITIALIZER_P.
 

gcc/cp/pt.c

@@ -25097,14 +25097,14 @@ maybe_instantiate_noexcept (tree fn, tsubst_flags_t complain)
       TREE_TYPE (fn) = build_exception_variant (fntype, spec);
       if (orig_fn)
 	TREE_TYPE (orig_fn) = TREE_TYPE (fn);
+    }
 
-      FOR_EACH_CLONE (clone, fn)
-	{
-	  if (TREE_TYPE (clone) == fntype)
-	    TREE_TYPE (clone) = TREE_TYPE (fn);
-	  else
-	    TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
-	}
+  FOR_EACH_CLONE (clone, fn)
+    {
+      if (TREE_TYPE (clone) == fntype)
+	TREE_TYPE (clone) = TREE_TYPE (fn);
+      else
+	TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
     }
 
   return true;