Fix issue 10991 - Implement __traits(getVirtualIndex).

Minor tweaks to __traits(getVirtualIndex).
Add unit test for __traits(getVirtualIndex).

Added additional test for final overrides.

Fixed formatting for virtual index test.
Formatting: moved else block to separate line.
Another incorrect brace fix.
Fix dmd.conf man section number
Merge pull request #2543 from leandro-lucarella-sociomantic/dmd.conf.5-fix-dmd2

Fix dmd.conf man section number
Merge pull request #2541 from 9rnsr/fix10980

Issue 10998 (REG 2.063) & Issue Issue 10980 - fix for compile-time postblit  call check
Merge pull request #2540 from 9rnsr/fix_main

Fix genCmain code to remove ambiguity of `&main` expression
Merge pull request #2536 from Kapps/fix10991

Fix issue 10991 - implement __traits(getVirtualIndex)
Set INCLUDE environment when MSVC++ compiler called (Use /I=dir option)