[proxies] Use IsRevoked where possible, remove has_handler.

src/messages.h

Index: src/messages.h
diff --git a/src/messages.h b/src/messages.h
index e5fa5fc31a513f071fe2b5c62ebe0c1cc3e51f23..501c7166f0349ac6137fe12c103133470fa793c6 100644
--- a/src/messages.h
+++ b/src/messages.h
@@ -200,6 +200,8 @@ class CallSite {
     "Proxy handler % returned non-configurable descriptor for property '%' "   \
     "from '%' trap")                                                           \
   T(ProxyRepeatedPropName, "Trap '%' returned repeated property name '%'")     \
+  T(ProxyHandlerOrTargetRevoked,                                               \
+    "Cannot create proxy with a revoked proxy as handler or target")           \
   T(ProxyRevoked, "Cannot perform '%' on a proxy that has been revoked")       \
   T(ProxyTargetNotExtensible, "Proxy target is not extensible")                \
   T(ProxyTargetNonObject, "Proxy target is non-object")                        \