[Issue 21944] importC: Support parsing # line marker directive extensions

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=21944

Iain Buclaw <ibuclaw at gdcproject.org> changed:

           What    |Removed                     |Added
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           Keywords|                            |importC
                 CC|                            |ibuclaw at gdcproject.org

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