I looked at the errors:
/Users/steves/.dvm/compilers/dmd-2.071.1/osx/bin/../../src/phobos/std/range/package.d(4751): Error: cannot implicitly convert expression (cast(int)pastLast - 1) of type int to ushort
/Users/steves/.dvm/compilers/dmd-2.071.1/osx/bin/../../src/phobos/std/range/package.d(4756): Error: cannot implicitly convert expression (cast(int)pastLast + 1) of type int to ushort
/Users/steves/.dvm/compilers/dmd-2.071.1/osx/bin/../../src/phobos/std/range/package.d(4773): Error: cannot implicitly convert expression (cast(int)this.pastLast - cast(int)this.step) of type int to inout(ushort)
We are just adding/subtracting 1 or step in each of these. Just cast to the correct type, should be sufficient. Alternatively, you can use += or -= instead.
May need to `static if` this fix for only builtin types, as custom types probably already handle the operations correctly, and we don't want to mess with that.