Implement function proxies (except for their use as constructors).

src/objects-printer.cc

Index: src/objects-printer.cc
diff --git a/src/objects-printer.cc b/src/objects-printer.cc
index 35735724e8717289e574c35aa8764ef9a0ada490..0398572f90c8cee81e6eb6c06417dd1de19bf57b 100644
--- a/src/objects-printer.cc
+++ b/src/objects-printer.cc
@@ -151,6 +151,9 @@ void HeapObject::HeapObjectPrint(FILE* out) {
     case JS_PROXY_TYPE:
       JSProxy::cast(this)->JSProxyPrint(out);
       break;
+    case JS_FUNCTION_PROXY_TYPE:
+      JSFunctionProxy::cast(this)->JSFunctionProxyPrint(out);
+      break;
     case JS_WEAK_MAP_TYPE:
       JSWeakMap::cast(this)->JSWeakMapPrint(out);
       break;
@@ -588,6 +591,19 @@ void JSProxy::JSProxyPrint(FILE* out) {
 }
 
 
+void JSFunctionProxy::JSFunctionProxyPrint(FILE* out) {
+  HeapObject::PrintHeader(out, "JSFunctionProxy");
+  PrintF(out, " - map = 0x%p\n", reinterpret_cast<void*>(map()));
+  PrintF(out, " - handler = ");
+  handler()->Print(out);
+  PrintF(out, " - call_trap = ");
+  call_trap()->Print(out);
+  PrintF(out, " - construct_trap = ");
+  construct_trap()->Print(out);
+  PrintF(out, "\n");
+}
+
+
 void JSWeakMap::JSWeakMapPrint(FILE* out) {
   HeapObject::PrintHeader(out, "JSWeakMap");
   PrintF(out, " - map = 0x%p\n", reinterpret_cast<void*>(map()));