[libFuzzer] Use macro instead of __attribute__.

This should fix the Windows buildbot errors.

GitOrigin-RevId: 4b82f614745bfcd39e7cc546803f8eb69082a712
diff --git a/FuzzerLoop.cpp b/FuzzerLoop.cpp
index f502826..149742b 100644
--- a/FuzzerLoop.cpp
+++ b/FuzzerLoop.cpp
@@ -580,8 +580,8 @@
 
 // This method is not inlined because it would cause a test to fail where it
 // is part of the stack unwinding. See D97975 for details.
-void __attribute__((noinline))
-Fuzzer::ExecuteCallback(const uint8_t *Data, size_t Size) {
+ATTRIBUTE_NOINLINE void Fuzzer::ExecuteCallback(const uint8_t *Data,
+                                                size_t Size) {
   TPC.RecordInitialStack();
   TotalNumberOfRuns++;
   assert(InFuzzingThread());