[iwyu] Include handles.h less.

src/accessors.h

Index: src/accessors.h
diff --git a/src/accessors.h b/src/accessors.h
index 218fb3572ff75ec345e9da422a4922f0cbfb094c..a4d51fd18abfc41c97d35f1746eb8a91d02d9ef4 100644
--- a/src/accessors.h
+++ b/src/accessors.h
@@ -8,7 +8,6 @@
 #include "include/v8.h"
 #include "src/allocation.h"
 #include "src/globals.h"
-#include "src/handles.h"
 #include "src/property-details.h"
 
 namespace v8 {
@@ -16,6 +15,8 @@ namespace internal {
 
 // Forward declarations.
 class AccessorInfo;
+template <typename T>
+class Handle;
 
 // The list of accessor descriptors. This is a second-order macro
 // taking a macro to be applied to all accessor descriptor names.