[Issue 21974] importC: Error: undefined identifier '__builtin_va_list'

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=21974

--- Comment #8 from Iain Buclaw <ibuclaw at gdcproject.org> ---
(In reply to Walter Bright from comment #6)
> Those last three look like they were added before gcc could handle inline
> functions.
More like, it existed before gcc recognized bswap as an intrinsic.

The original code from bits/byteswap.h:
---
static __inline __uint32_t
__bswap_32 (__uint32_t __bsx)
{
#if __GNUC_PREREQ (4, 3)
  return __builtin_bswap32 (__bsx);
#else
  return __bswap_constant_32 (__bsx);
#endif
}
---

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