Implement DUALNUM for math.abs & fix divide operation bug.

  For Lua, the internal number type is double float. for divide
operation, integer divide actually produce different result with
float divide, such as 3/4 and 3.0/4.

  So, under DUALNUM mode, even the number could be represented by
integer type, we still need to use float divide instead of integer
divide, which means for TileGX, we need to convert the integer to
float, then do float divide.
Fix global label branch relocation bug. Pass the whole SCI benchmark.