[Proxies] Support constructable proxy as new.target (reland)

src/ia32/builtins-ia32.cc

Index: src/ia32/builtins-ia32.cc
diff --git a/src/ia32/builtins-ia32.cc b/src/ia32/builtins-ia32.cc
index 3762be8d784d1a0596276bc7f099e6e5f34d3fae..9473a925ae73d8a1cf7457c008363d4e68b7253d 100644
--- a/src/ia32/builtins-ia32.cc
+++ b/src/ia32/builtins-ia32.cc
@@ -1608,10 +1608,9 @@ void Builtins::Generate_Call(MacroAssembler* masm, ConvertReceiverMode mode) {
 void Builtins::Generate_ConstructFunction(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- eax : the number of arguments (not including the receiver)
-  //  -- edx : the new target (checked to be a JSFunction)
+  //  -- edx : the new target (checked to be a constructor)
   //  -- edi : the constructor to call (checked to be a JSFunction)
   // -----------------------------------
-  __ AssertFunction(edx);
   __ AssertFunction(edi);
 
   // Calling convention for function specific ConstructStubs require