Fix Issue 11819 - Implement better diagnostics for unrecognized traits.
Merge pull request #3507 from AndrejMitrovic/Fix11819

Issue 11819 - Implement better diagnostics for unrecognized traits.
refactor IntegerExp
Merge pull request #3495 from WalterBright/refactor-IntegerExp

refactor IntegerExp
Fix build on OpenSolaris.

With these changes, dmd compiles on OpenSolaris 11.1.
Fix Issue 12678 - Field constness missing in diagnostics for multiple field initialization error.
Merge pull request #3512 from redstar/solaris

Fix build on OpenSolaris.
Merge pull request #3511 from AndrejMitrovic/Fix12678

Issue 12678 - Field constness missing in diagnostics for multiple field initialization error.