Add a test of uint -> uint64 conversion.
library/uint64.m:
Fix a typo that broke uint64.cast_from_uint/1.
tests/hard_coded/Mmakefile:
tests/hard_coded/from_uint_uint64.{m,exp,exp2}:
Add a test of uint -> uint64 conversion.
tests/hard_coded/from_int_int*.m:
tests/hard_coded/from_uint_uint*.m:
Fix errors in comments.
