[gcc r12-1919] c++: don't treat member var as var template

[gcc r12-1919] c++: don't treat member var as var template

[Jason Merrill]

https://gcc.gnu.org/g:362347c5a4e56d48c9af7ed7d9cc3feff0c2d219

commit r12-1919-g362347c5a4e56d48c9af7ed7d9cc3feff0c2d219
Author: Jason Merrill <jason@redhat.com>
Date:   Tue Jun 29 15:11:25 2021 -0400

    c++: don't treat member var as var template
    
    While looking at a partial instantiation issue I noticed that we were
    wrongly hitting the partial instantiation code when instantiating a static
    data member of a class template.  I don't think this broke anything, but we
    don't need to do that (small) extra work.
    
    gcc/cp/ChangeLog:
    
            * pt.c (instantiate_decl): Only consider partial specializations of
            actual variable templates.

Diff:
---
 gcc/cp/pt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index f2039e09cd7..d2936c106ba 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -26003,7 +26003,7 @@ instantiate_decl (tree d, bool defer_ok, bool expl_inst_class_mem_p)
   td = template_for_substitution (d);
   args = gen_args;
 
-  if (VAR_P (d))
+  if (variable_template_specialization_p (d))
     {
       /* Look up an explicit specialization, if any.  */
       tree tid = lookup_template_variable (gen_tmpl, gen_args);