0.16.3

Added

• random input blocks for futhark test and futhark bench now
  support floating-point literals, which must always have either an
  f32 or f64 suffix.

• The cuda backend now supports the -d option for executables.

• The integer modules now contain a ctz function for counting
  trailing zeroes.

Fixed

• The pyopencl backend now works with OpenCL devices that have
  multiple types (most importantly, oclgrind).

• Fix barrier divergence when generating code for group-level
  colletive copies in GPU backend.

• Intra-group flattening now looks properly inside of branches.

• Intra-group flattened code versions are no longer used when the
  resulting workgroups would have less than 32 threads (with default
  thresholds anyway) (#1064).