Fix handling arrays with holes in JSON.stringify.

test/mjsunit/json2.js

Index: test/mjsunit/json2.js
diff --git a/test/mjsunit/regress/regress-2110.js b/test/mjsunit/json2.js
similarity index 74%
copy from test/mjsunit/regress/regress-2110.js
copy to test/mjsunit/json2.js
index d7f78d26a7b4d16c4217d2b0ac136e52e4542eb1..c4392401ce74cfe501666182de515313b2771896 100644
--- a/test/mjsunit/regress/regress-2110.js
+++ b/test/mjsunit/json2.js
@@ -27,27 +27,22 @@
 
 // Flags: --allow-natives-syntax
 
-var uint8 = new Uint8Array(1);
+var fast_smi = [1, 2, 3, 4];
+fast_smi.__proto__ = [7, 7, 7, 7];
+delete fast_smi[2];
+assertTrue(%HasFastSmiElements(fast_smi));
+assertEquals("[1,2,7,4]", JSON.stringify(fast_smi));
 
-function test() {
-  uint8[0] = 0x800000aa;
-  assertEquals(0xaa, uint8[0]);
-}
+var fast_double = [1.1, 2, 3, 4];
+fast_double.__proto__ = [7, 7, 7, 7];
 
-test();
-test();
-test();
-%OptimizeFunctionOnNextCall(test);
-test();
+delete fast_double[2];
+assertTrue(%HasFastDoubleElements(fast_double));
+assertEquals("[1.1,2,7,4]", JSON.stringify(fast_double));
 
-var uint32 = new Uint32Array(1);
+var fast_obj = [1, 2, {}, {}];
+fast_obj.__proto__ = [7, 7, 7, 7];
 
-function test2() {
-  uint32[0] = 0x80123456789abcde;
-  assertEquals(0x789ac000, uint32[0]);
-}
-
-test2();
-test2();
-%OptimizeFunctionOnNextCall(test2);
-test2();
+delete fast_obj[2];
+assertTrue(%HasFastObjectElements(fast_obj));
+assertEquals("[1,2,7,{}]", JSON.stringify(fast_obj));