Remove inline header includes from natives.h header.

src/snapshot/natives-external.cc

Index: src/snapshot/natives-external.cc
diff --git a/src/snapshot/natives-external.cc b/src/snapshot/natives-external.cc
index 94fc2c11ff8c4aa950d9b14f767ed527732405a8..e0df27f3ad5c20c41433b1724f6c8dbe345c8dcf 100644
--- a/src/snapshot/natives-external.cc
+++ b/src/snapshot/natives-external.cc
@@ -229,11 +229,19 @@ Vector<const char> NativesCollection<type>::GetScriptsSource() {
 }
 
 
-// The compiler can't 'see' all uses of the static methods and hence
-// my choice to elide them. This we'll explicitly instantiate these.
-template class NativesCollection<CORE>;
-template class NativesCollection<CODE_STUB>;
-template class NativesCollection<EXPERIMENTAL>;
-template class NativesCollection<EXTRAS>;
+// Explicit template instantiations.
+#define INSTANTIATE_TEMPLATES(T)                                            \
+  template int NativesCollection<T>::GetBuiltinsCount();                    \
+  template int NativesCollection<T>::GetDebuggerCount();                    \
+  template int NativesCollection<T>::GetIndex(const char* name);            \
+  template Vector<const char> NativesCollection<T>::GetScriptSource(int i); \
+  template Vector<const char> NativesCollection<T>::GetScriptName(int i);   \
+  template Vector<const char> NativesCollection<T>::GetScriptsSource();
+INSTANTIATE_TEMPLATES(CORE)
+INSTANTIATE_TEMPLATES(CODE_STUB)
+INSTANTIATE_TEMPLATES(EXPERIMENTAL)
+INSTANTIATE_TEMPLATES(EXTRAS)
+#undef INSTANTIATE_TEMPLATES
+
 }  // namespace internal
 }  // namespace v8