gltrace: Avoid __libc_dlsym and __libc_dlopen_mode on GLIBC 2.34.

These GLIBC_PRIVATE symbols are gone from GLIBC 2.34 due to the merge of
libdl.so onto libc.so.

This means apitrace can't defend against infinite recursion when
used with Steam Overlay, but at least it should work otherwise.

Fixes https://github.com/apitrace/apitrace/issues/756

BUG=b:219796708
TEST=builds with patch
(cherry picked from commit d28a980802ad48568c87da02d630c8babfe163bb)
Signed-off-by: David Riley <davidriley@chromium.org>
Change-Id: I5e61b8cf3e9f8a8687167906a360b5af24ca3dc8
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/apitrace/+/3466574
Reviewed-by: Ilja Friedel <ihf@chromium.org>
Commit-Queue: Ilja Friedel <ihf@chromium.org>
1 file changed