Detabify StgCmmMonad
Detabify StgCmmEnv
Remove cg_tag from CgIdInfo
Remove unused functions cmmConstrTag, cmmGetTag

Patch offered by Boris Sukholitko <boriss@gmail.com>
Trac #7757
Fix pretty printing of human-readable integers (#7750)
Remove warning-suppression (not needed)
Remove stale, commented-out code about heap checks
Remove unnecessary DynFlags arg to mkCgIdInfo
Slight tidy-up to Pedro's work on Typeable