[COMMITTED] bpf: disable tail call optimization in BPF targets

[Jose E. Marchesi via Gcc-patches]

clang disables tail call optimizations in BPF targets.  Do the same in
GCC.

gcc/ChangeLog:

        * config/bpf/bpf.cc (bpf_option_override): Disable tail-call
        optimizations in BPF target.
---
 gcc/config/bpf/bpf.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
index b5b5674edbb..57817cdf2f8 100644
--- a/gcc/config/bpf/bpf.cc
+++ b/gcc/config/bpf/bpf.cc
@@ -273,6 +273,9 @@ bpf_option_override (void)
              "on this architecture");
       flag_stack_protect = 0;
     }
+
+  /* The BPF target does not support tail call optimization.  */
+  flag_optimize_sibling_calls = 0;
 }
 
 #undef TARGET_OPTION_OVERRIDE
-- 
2.30.2