Treat leading zeros in JSON.parse correctly.

test/mjsunit/regress/regress-crbug-158185.js

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-var string = "What are you looking for?";
+assertEquals("0023456",
+             Object.keys(JSON.parse('{"0023456": 1}'))[0]);
+assertEquals("1234567890123",
+             Object.keys(JSON.parse('{"1234567890123": 1}'))[0]);
+assertEquals("123456789ABCD",
+             Object.keys(JSON.parse('{"123456789ABCD": 1}'))[0]);
+assertEquals("12A",
+             Object.keys(JSON.parse('{"12A": 1}'))[0]);
 
-var expected_match = [""];
-for (var i = 0; i < string.length; i++) {
-  expected_match.push("");
-}
+assertEquals(1, JSON.parse('{"0":1}')[0]);
+assertEquals(undefined, JSON.parse('{"00":1}')[0]);
 
-string.replace(/(_)|(_|)/g, "");
-assertArrayEquals(expected_match, string.match(/(_)|(_|)/g, ""));
-
-'***************************************'.match(/((\\)|(\*)|(\$))/g, ".");