[Issue 24310] ImportC: varargs from Microsoft header incompatible with va_start

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=24310

--- Comment #3 from Walter Bright <bugzilla at digitalmars.com> ---
Currently,

1. there is no va_start in importc.h

2. in __builtins.di there is:

    alias __builtin_va_start = imported!"core.stdc.stdarg".va_start;

3. in Microsoft's stdarg.h there is:

    #define va_start __crt_va_start

4. in core.stdc.stdarg there is:

    void va_start(T)(out va_list ap, ref T parmn);

va_start() is an intrinsic built in to dmd.

Is __va_start() a Microsoft intrinsic?

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