[PATCH] Only use fast stack unwinding for sanitizers failure reports on FreeBSD

[Viktor Kutuzov]

================
Comment at: lib/sanitizer_common/sanitizer_stacktrace.h:60
@@ -56,3 +59,3 @@
       return false;
-    else if (SANITIZER_MAC)
+    else if (SANITIZER_MAC != 0 || SANITIZER_FREEBSD != 0)
       return true;
----------------
'if (SANITIZER_MAC || SANTIIZER_FREEBSD)' gives the 'use of logical '||' with constant operand' kind of warning.

http://reviews.llvm.org/D4420