Mark __dso_handle as hidden [BZ #18822]

Since __dso_handle is always defined by either crtbegin.o from GCC or
dso_handle.c, it should be marked as hidden and be passed directly.

	[BZ #18822]
	* dlfcn/modatexit.c (foo): Remove __dso_handle check.
	* dlfcn/modcxaatexit.c: Include <dso_handle.h>.
	(__dso_handle): Remove declaration.
	* dlfcn/tstatexit.c (__dso_handle): Removed.
	(main): Don't check __dso_handle.
	* dlfcn/tstcxaatexit.c (__dso_handle): Removed.
	(main): Don't check __dso_handle.
	* include/dso_handle.h: New file.
	* malloc/mtrace.c: Include <dso_handle.h>.
	(mtrace): Pass __dso_handle directly.
	* nptl/pthread_atfork.c: Include <dso_handle.h>.
	(__dso_handle): Remove declaration.
	(__pthread_atfork): Pass __dso_handle directly.
	* nptl/tst-atfork2mod.c: Include <dso_handle.h>.
	(__dso_handle): Removed.
	* posix/wordexp-test.c: Include <dso_handle.h>.
	(__dso_handle): Remove declaration.
	(__app_register_atfork): Pass __dso_handle directly.
	* stdlib/at_quick_exit.c: Include <dso_handle.h>.
	(__dso_handle): Remove declaration.
	(at_quick_exit): Pass __dso_handle directly.
	* stdlib/atexit.c: Include <dso_handle.h>.
	(__dso_handle): Remove declaration.
	(atexit): Pass __dso_handle directly.
	* stdlib/tst-tls-atexit-lib.c: Include <dso_handle.h>.
	(__dso_handle): Removed.

1 files changed, 3 insertions, 0 deletions

diff --git a/include/dso_handle.h b/include/dso_handle.h
new file mode 100644
index 0000000000..d9c1ebbce4
--- /dev/null
+++ b/include/dso_handle.h
@@ -0,0 +1,3 @@
+/* __dso_handle is always defined by either crtbegin.o from GCC or our
+   dso_handle.c.  */
+extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));