StringToInt rewritten. This version doesn't allocate memory for long decimals...

test/mjsunit/str-to-num.js

 // Copyright 2008 the V8 project authors. All rights reserved.
 // 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
@@ skipping 44 matching lines @@
 assertEquals(123, toNumber("123\r"));
 assertEquals(123, toNumber("123\t"));
 assertEquals(123, toNumber("123\f"));
 
 assertEquals(123, toNumber(" 123 "));
 assertEquals(123, toNumber("\n123\n"));
 assertEquals(123, toNumber("\r123\r"));
 assertEquals(123, toNumber("\t123\t"));
 assertEquals(123, toNumber("\f123\f"));
 
+assertEquals(16, toNumber(" 0x10 "));
+assertEquals(NaN, toNumber("0x"));
+assertEquals(NaN, toNumber("0x "));
+
 assertTrue(isNaN(toNumber(" NaN ")));
 assertEquals(Infinity,  toNumber(" Infinity ") ," Infinity");
 assertEquals(-Infinity, toNumber(" -Infinity "));
 assertEquals(Infinity,  toNumber(" +Infinity "), " +Infinity");
 assertEquals(Infinity,  toNumber("Infinity ") ,"Infinity");
 assertEquals(-Infinity, toNumber("-Infinity "));
 assertEquals(Infinity,  toNumber("+Infinity "), "+Infinity");
 
 assertEquals(0,  toNumber("0"));
 assertEquals(0,  toNumber("+0"));
@@ skipping 117 matching lines @@
 
 assertTrue(isNaN(toNumber("junk")), "junk");
 assertTrue(isNaN(toNumber("100 junk")), "100 junk");
 assertTrue(isNaN(toNumber("0x100 junk")), "0x100 junk");
 assertTrue(isNaN(toNumber("100.0 junk")), "100.0 junk");
 assertTrue(isNaN(toNumber(".1e4 junk")), ".1e4 junk");
 assertTrue(isNaN(toNumber("Infinity junk")), "Infinity junk");
 assertTrue(isNaN(toNumber("1e")), "1e");
 assertTrue(isNaN(toNumber("1e ")), "1e_");
 assertTrue(isNaN(toNumber("1" + repeat('0', 1000) + 'junk')), "1e1000 junk");