fix Issue 12651 - TemplateArgsOf accepts nonsensical arguments
Fix Issue 11511 - DDoc - C variadic parameters cannot be properly documented.
Fix Issue 12653 - Implement the getFunctionAttributes trait.
Merge pull request #3501 from AndrejMitrovic/Fix12653

Issue 12653 - Implement the getFunctionAttributes trait.
Merge pull request #3502 from 9rnsr/fix12651

Issue 12651 - TemplateArgsOf accepts nonsensical arguments
Merge pull request #3503 from AndrejMitrovic/Fix11511

Issue 11511 - DDoc C variadic parameters cannot be properly documented.