lib Fuzzer FreeBSD support

Summary: Patch by David CARLIER

Reviewers: vitalybuka, kcc, dim, emaste, davide, morehouse, george.karpenkov

Reviewed By: morehouse

Subscribers: george.karpenkov, kubamracek, srhines, mgorny, emaste, krytarowski

Differential Revision: https://reviews.llvm.org/D41642

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer@322380 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/FuzzerExtraCounters.cpp b/FuzzerExtraCounters.cpp
index 0e7a776..d98598a 100644
--- a/FuzzerExtraCounters.cpp
+++ b/FuzzerExtraCounters.cpp
@@ -11,7 +11,7 @@
 
 #include "FuzzerDefs.h"
 
-#if LIBFUZZER_LINUX || LIBFUZZER_NETBSD
+#if LIBFUZZER_LINUX || LIBFUZZER_NETBSD || LIBFUZZER_FREEBSD
 __attribute__((weak)) extern uint8_t __start___libfuzzer_extra_counters;
 __attribute__((weak)) extern uint8_t __stop___libfuzzer_extra_counters;