Add GC request to libFuzzers in attempt to avoid parasitic coverage.

test/fuzzer/fuzzer-support.cc

Index: test/fuzzer/fuzzer-support.cc
diff --git a/test/fuzzer/fuzzer-support.cc b/test/fuzzer/fuzzer-support.cc
index cf3ee8c6fddcde8030e9419ba6147ac77de1dd0d..a0dafd0616e29044604a7b40476060c2ab11676d 100644
--- a/test/fuzzer/fuzzer-support.cc
+++ b/test/fuzzer/fuzzer-support.cc
@@ -10,6 +10,8 @@
 
 #include "include/libplatform/libplatform.h"
 
+#include "src/flags.h"
+
 namespace v8_fuzzer {
 
 namespace {
@@ -36,6 +38,7 @@ class FuzzerSupport::ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
 };
 
 FuzzerSupport::FuzzerSupport(int* argc, char*** argv) {
+  v8::internal::FLAG_expose_gc = true;
   v8::V8::SetFlagsFromCommandLine(argc, *argv, true);
   v8::V8::InitializeICU();
   v8::V8::InitializeExternalStartupData((*argv)[0]);