Merge pull request #298 from redstar/bitops

Fix big-endian code generation for btc, btr and bts.
Simple part of removing D1
Remove DMDV1 and DMDV2.
Remove STRUCTTHISREF
Remove SARRAYVALUE
Removed a few D1 leftovers.
Merge of DMD 2.062.
Change naked asm functions to accept enum declaration.

An enum defines constant values which can be used without trouble in
naked asm functions.