[PATCH] Fix function, tsubst_requires_expr for callers to tsubst_constraint_variables

[Nicholas Krause]

This fixes both callers in tsubst_requires_expr to
tsubst_constraint_variables to wrap their respective
trees in PARM_CONSTR_PARMS. This is to get the correct
parmeter constraints from the tree before calling
tsubst_constraint_variables like other callers
in constraint.cc and to avoid subtle bugs in the
future.

Signed-off-by: Nicholas Krause <xerofo...@gmail.com>
---
 gcc/cp/constraint.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gcc/cp/constraint.cc b/gcc/cp/constraint.cc
index 9884eb0db50..cb06d0ec6e2 100644
--- a/gcc/cp/constraint.cc
+++ b/gcc/cp/constraint.cc
@@ -1882,13 +1882,13 @@ tsubst_requires_expr (tree t, tree args,
   tree parms = TREE_OPERAND (t, 0);
   if (parms)
     {
-      parms = tsubst_constraint_variables (parms, args, complain, in_decl);
+      parms = tsubst_constraint_variables (PARM_CONSTR_PARMS (parms), args, 
complain, in_decl);
       if (parms == error_mark_node)
         return error_mark_node;
     }
 
   tree reqs = TREE_OPERAND (t, 1);
-  reqs = tsubst_requirement_body (reqs, args, complain, in_decl);
+  reqs = tsubst_requirement_body (PARM_CONSTR_PARMS (reqs), args, complain, 
in_decl);
   if (reqs == error_mark_node)
     return error_mark_node;
 
-- 
2.17.1