[patch,openacc] Fix infinite recursion in OMP clause pretty-printing, default label

[Cesar Philippidis]

Apparently, Tom ran into an ICE when we were adding support for new
clauses back in the gomp-4_0-branch days.  This patch shouldn't be
necessary because all of the clauses are fully implemented now, but
it may prevent similar bugs from occurring in the future at least
during development.

Is this patch OK for trunk? I bootstrapped and regtested it for x86_64
Linux with nvptx offloading.

Thanks,
Cesar

Fix infinite recursion in OMP clause pretty-printing, default label

Apparently, Tom ran into an ICE when we were adding support for new
clauses back in the gomp-4_0-branch days.  This patch shouldn't be
necessary because all of the clauses are fully implemented now, but
it may prevent similar bugs from occuring in the future at least
during development.

2018-XX-YY  Tom de Vries  <tdevr...@suse.de>
            Cesar Philippidis  <ce...@codesourcery.com>

	gcc/
	* tree-pretty-print.c (dump_omp_clause): Fix infinite recursion in
	default label.

(cherry picked from gomp-4_0-branch r228915, 2e4d930)
---
 gcc/tree-pretty-print.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/gcc/tree-pretty-print.c b/gcc/tree-pretty-print.c
index 2c089b11751..031afbb49e4 100644
--- a/gcc/tree-pretty-print.c
+++ b/gcc/tree-pretty-print.c
@@ -1063,8 +1063,7 @@ dump_omp_clause (pretty_printer *pp, tree clause, int spc, dump_flags_t flags)
       break;
 
     default:
-      /* Should never happen.  */
-      dump_generic_node (pp, clause, spc, flags, false);
+      pp_string (pp, "unknown");
       break;
     }
 }
-- 
2.17.1