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 Issue 9073 - In manifest constant initializer, && and || should evaluate their operands lazily.
fix Issue 10998 - compile-time postblit call check is incorrectly suppressed

In the pull request #1801, I had forgot to remove the *ungag* code. That was caused the incorrect gagging regression.
[trivial] fix fail341.d mistake

AFAICS, `@nocall` is a mistake of `@disable`.
Fix issue 10858 CTFE wrong array of pointers

Pointer comparison should be based on rvalues, not lvalues.
That bug was also hiding three latent wrong-code bugs.
fix Issue 10980 - static initialization of immutable structs with disabled postblit fails
Fix genCmain code to remove ambiguity of `&main` expression

It was introduced by pull#2476, but the expression `&main` which is implicitly
inserted would conflict with two extern(C) and (D) "main" functions in
user module.

Instead, separate the entry-point code in the hidden module __entrypoint.d

Compiler will emit the generated C-main code in the same object file that
contains D-main code.
Fix compiler segfault with main function and -lib switch
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)
Merge pull request #1325 from 9rnsr/fix9073

Issue 9073 - In manifest constant initializer, && and || should evaluate their operands lazily.
Merge pull request #2527 from donc/badpointer10858ctfe

10858 CTFE wrong-code for array of pointers
revert pull 1325
Merge pull request #2547 from WalterBright/revert-pull-1325

revert pull 1325