c++/modules: Fix linkage checks for exported using-declsHEADtrunkmaster

This patch attempts to fix an error when build module std. The reason for
the error is __builtin_va_list (aka struct __va_list) has internal linkage.
so mark this builtin type as TREE_PUBLIC to make struct __va_list has
external linkage.

g++ -fmodules -std=c++23 -fsearch-include-path bits/std.cc -c
std.cc:3642:14:error: exporting ‘typedef __gnuc_va_list va_list’ that does not have external linkage
 3642 |   using std::va_list;
      |              ^~~~~~~
<built-in>: note: ‘struct __va_list’ declared here with internal linkage

gcc/ChangeLog:

	* config/aarch64/aarch64.cc (aarch64_build_builtin_va_list): Mark
	__builtin_va_list as TREE_PUBLIC.
	* config/arm/arm.cc (arm_build_builtin_va_list): Likewise.

gcc/testsuite/ChangeLog:

	* g++.dg/modules/builtin-8.C: New test.

Reviewed-by: Jason Merrill <jason@redhat.com>

0 files changed, 0 insertions, 0 deletions