[libFuzzer] experimental performance optimization -lazy_counters, off by default. Posix-only for now, tested on Linux

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer@352700 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/FuzzerUtilFuchsia.cpp b/FuzzerUtilFuchsia.cpp
index bef4192..7b5c8f6 100644
--- a/FuzzerUtilFuchsia.cpp
+++ b/FuzzerUtilFuchsia.cpp
@@ -287,6 +287,10 @@
 
 } // namespace
 
+bool Mprotect(void *Ptr, size_t Size, bool AllowReadWrite) {
+  return false;  // UNIMPLEMENTED
+}
+
 // Platform specific functions.
 void SetSignalHandler(const FuzzingOptions &Options) {
   // Set up alarm handler if needed.