8252995: Non-PCH builds broken by JDK-8250961

Reviewed-by: sjohanss, stefank

Author: Kim Barrett

src/hotspot/share/gc/shared/referencePolicy.cpp

@@ -24,6 +24,7 @@
 
 #include "precompiled.hpp"
 #include "classfile/javaClasses.hpp"
+#include "gc/shared/collectedHeap.hpp"
 #include "gc/shared/referencePolicy.hpp"
 #include "memory/universe.hpp"
 #include "runtime/arguments.hpp"