[gcc r13-7279] Revert "c++: *this folding in constexpr call"

[Jason Merrill <jason@gcc.gnu.org>]

https://gcc.gnu.org/g:275e059dd7542f0d45adba74de18296134ac0d15

commit r13-7279-g275e059dd7542f0d45adba74de18296134ac0d15
Author: Jason Merrill <jason@redhat.com>
Date:   Tue May 2 15:03:57 2023 -0400

    Revert "c++: *this folding in constexpr call"
    
    The earlier commit wasn't fixing a known bug, so let's revert it on the
    branch.
    
            PR c++/109678
    
    This reverts commit 1189c03859cefef4fc4fd44d57eb3d4d3348b562.

Diff:
---
 gcc/cp/constexpr.cc | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/gcc/cp/constexpr.cc b/gcc/cp/constexpr.cc
index d1097764b10..56329dcc9e0 100644
--- a/gcc/cp/constexpr.cc
+++ b/gcc/cp/constexpr.cc
@@ -1440,8 +1440,6 @@ enum value_cat {
 
 static tree cxx_eval_constant_expression (const constexpr_ctx *, tree,
 					  value_cat, bool *, bool *, tree * = NULL);
-static tree cxx_fold_indirect_ref (const constexpr_ctx *, location_t, tree, tree,
-				   bool * = NULL);
 static tree find_heap_var_refs (tree *, int *, void *);
 
 /* Attempt to evaluate T which represents a call to a builtin function.
@@ -2956,7 +2954,9 @@ cxx_eval_call_expression (const constexpr_ctx *ctx, tree t,
 	 At this point it has already been evaluated in the call
 	 to cxx_bind_parameters_in_call.  */
       new_obj = TREE_VEC_ELT (new_call.bindings, 0);
-      new_obj = cxx_fold_indirect_ref (ctx, loc, DECL_CONTEXT (fun), new_obj);
+      STRIP_NOPS (new_obj);
+      if (TREE_CODE (new_obj) == ADDR_EXPR)
+	new_obj = TREE_OPERAND (new_obj, 0);
 
       if (ctx->call && ctx->call->fundef
 	  && DECL_CONSTRUCTOR_P (ctx->call->fundef->decl))
@@ -5474,8 +5474,7 @@ cxx_fold_indirect_ref_1 (const constexpr_ctx *ctx, location_t loc, tree type,
 	  && CLASS_TYPE_P (optype)
 	  && DERIVED_FROM_P (type, optype))
 	{
-	  if (empty_base)
-	    *empty_base = true;
+	  *empty_base = true;
 	  return op;
 	}
     }
@@ -5494,7 +5493,7 @@ cxx_fold_indirect_ref_1 (const constexpr_ctx *ctx, location_t loc, tree type,
 
 static tree
 cxx_fold_indirect_ref (const constexpr_ctx *ctx, location_t loc, tree type,
-		       tree op0, bool *empty_base /* = NULL*/)
+		       tree op0, bool *empty_base)
 {
   tree sub = op0;
   tree subtype;