Reviewed by Darin.

        <rdar://problem/5327189> Logic error in DeprecatedString::to{,U}Int{,64} can lead to reading past end of buffer

        The fix for reading past the end of the buffer is to verify we are not at the end of the string before checking
        for a leading '+' character.  Rather than fixing the logic error in four nearly-identical functions I chose to
        extract the common functionality into the toIntegralType helper function which the four functions call through to.

        * platform/DeprecatedString.cpp:
        (WebCore::isCharacterAllowedInBase):
        (WebCore::toIntegralType):
        (WebCore::DeprecatedString::toInt):
        (WebCore::DeprecatedString::toInt64):
        (WebCore::DeprecatedString::toUInt):
        (WebCore::DeprecatedString::toUInt64):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@24234 268f45cc-cd09-0410-ab3c-d52691b4dbfc