Remove arguments shadow from scopes, stop rewriting parameters.

arguments/src/ia32/full-codegen-ia32.cc

Index: arguments/src/ia32/full-codegen-ia32.cc
diff --git a/arguments/src/ia32/full-codegen-ia32.cc b/arguments/src/ia32/full-codegen-ia32.cc
index c8f5fdf65da818e9c6e394d9d3f0f83cd72b3f16..3e5a9848ab61fa91936ab152545398e0d74f0d8d 100644
--- a/arguments/src/ia32/full-codegen-ia32.cc
+++ b/arguments/src/ia32/full-codegen-ia32.cc
@@ -200,11 +200,6 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
     ArgumentsAccessStub stub(ArgumentsAccessStub::NEW_OBJECT);
     __ CallStub(&stub);
 
-    Variable* arguments_shadow = scope()->arguments_shadow();
-    if (arguments_shadow != NULL) {
-      __ mov(ecx, eax);  // Duplicate result.
-      Move(arguments_shadow->AsSlot(), ecx, ebx, edx);
-    }
     Move(arguments->AsSlot(), eax, ebx, edx);
   }