osrm-extract fails with very large size raster file.

[Tomonobu3110]

When we execute osrm-extract with very large raster file, osrm-exract consume too much memory and failed to finish execution.

For example...

raster_source = raster:load(
  "kanto13_ascii_osrm.asc",  -- file to load
  137.81250000000003,  -- longitude min
  141.328125,          -- longitude max
   34.88593094075317,  -- latitude min
   36.597889133070225, -- latitude max
  24576,               -- number of rows
  40960                -- number of columns

When I try to use raster file which size is 40960 x 24576 (zoom = 13 for whole Kanto (in Japan) area), I could not success the osrm-exract.

osrm-exract read more the one times and fails with below log message.

[info] [source loader] Loading from kanto13_ascii_osrm.asc  ...
terminate called after throwing an instance of 'tbb::captured_exception'
  what():  lua: error: Failed to read from raster source kanto13_ascii_osrm.asc: std::bad_allocinclude/extractor/raster_source.hpp:70
中止 (コアダンプ)