[performance] remove useless Array allocation
[performance] remove useless Array allocation

When parsing an object, arrays are first checked for.  The
code was allocating an Array, calling its parse method, and
then deallocating the Array on failure before allocatin an
Object to parse.  This patch will only allocate and parse
the Array if a left-bracket is found.

vltr/jsonxx-lite,DavadDi/jsonxx,hjiang/jsonxx,lethosor/jsonxx