Fixes Issue 1673 - Implement the isTemplate trait.
Fix Issue 13212 - Windows line endings handled incorrectly by ddoc macros

Handle \r as \n in macro definitions to prevent a trailing carriage
return on a macro with an empty line following it.
Fix Issue 12745 - [Ddoc] Underscore is removed from numbers
Test 2 underscores
Add DirectX library path

64-bit only. If 32-bit COFF support is ever added we can add that to the `Environment32` section as well.

Fixes #13265
Merge pull request #3380 from AndrejMitrovic/isTemplate

Issue 1673 - Implement the isTemplate trait.
Fix Issue 8269 - The 'with statement' does not observe temporary object lifetime
[Refactoring] Remove unused code for 'symfile'
[Refactoring] Remove unnecessary memset for HdrGenState

It's already done in the default constructor.
[Refactoring] Remove unused fields in HdrGenState
[Refactoring] Remove HdrGenState::console
Add Nspace into Visitor
Add TemplateParameter and its derived classes into Visitor
Add Condition and its derived classes into Visitor
Add Parameter into Visitor
[Refactoring] Rename FLinit.init to forStmtInit
Merge pull request #3856 from 9rnsr/fix_visitor

Add Nspace and others into Visitor
Merge pull request #3857 from 9rnsr/refactor_unused

[Refactoring] Remove unused code around header generation
Slim up test cases for header generation
[Refactoring] Remove Type::toCBuffer and use free function instead