Getter is called twice in railgun

GetSlot already calls getter.
So slot::Get call is not needed.

Author: Constellation

iv/lv5/railgun/operation.h

@@ -140,7 +140,7 @@ class Operation {
     if (!slot.IsLoadCacheable() || symbol::IsArrayIndexSymbol(s)) {
       // bailout to generic
       instr[0] = Instruction::GetOPInstruction(generic);
-      return slot.Get(ctx_, base, e);
+      return slot.value();
     }
 
     assert(!symbol::IsArrayIndexSymbol(s));

iv/lv5/test/suite/spec/getter-called-twice.js

@@ -0,0 +1,39 @@
+/*
+  Copyright (C) 2015 Yusuke Suzuki <[email protected]>
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+  DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+describe("regress", function() {
+  it("getter called twice", function() {
+      var count = 0;
+      var obj = {
+          get prop() {
+              ++count;
+              return 42;
+          }
+      };
+      obj.prop;
+      expect(count).toBe(1);
+  });
+});
+
+/* vim: set sw=4 ts=4 et tw=80 : */