c++: merge default targs for function templates [PR65396]
We currently merge default template arguments for class templates, but
not for function templates. This patch fixes this by factoring out the
argument merging logic in redeclare_class_template into a separate
function and using it in duplicate_decls as well.
PR c++/65396
gcc/cp/ChangeLog:
* cp-tree.h (merge_default_template_args): Declare.
* decl.cc (merge_default_template_args): Define, factored out
from redeclare_class_template.
(duplicate_decls): Use it when merging member function template
and free function declarations.
* pt.cc (redeclare_class_template): Factor out default argument
merging logic into merge_default_template_args. Improve location
of a note when there's a template parameter kind mismatch.
gcc/testsuite/ChangeLog:
* g++.dg/cpp0x/vt-34314.C: Adjust expected location of
"redeclared here" note.
* g++.dg/template/pr92440.C: Likewise.
* g++.old-deja/g++.pt/redecl1.C: Adjust expected location of
"redefinition of default argument" error.
* g++.dg/template/defarg23.C: New test.
* g++.dg/template/defarg23a.C: New test.