$NetBSD: patch-src_libaudcore_audio.h.in,v 1.1 2019/07/06 13:17:01 nia Exp $

NetBSD has these in libc.

--- src/libaudcore/audio.h.in.orig	2018-12-26 06:55:16.000000000 +0000
+++ src/libaudcore/audio.h.in
@@ -42,7 +42,10 @@ struct StereoVolume {
 };
 
 #ifdef WANT_AUD_BSWAP
-
+#ifdef __NetBSD__
+#include <sys/types.h>
+#include <machine/bswap.h>
+#else
 #include <stdint.h>
 
 #undef bswap16
@@ -66,7 +69,7 @@ constexpr uint64_t bswap64 (uint64_t x)
            ((x & 0x00000000ff000000) << 8) | ((x & 0x0000000000ff0000) << 24) |
            ((x & 0x000000000000ff00) << 40) | ((x & 0x00000000000000ff) << 56);
 }
-
+#endif // __NetBSD__
 #endif // WANT_AUD_BSWAP
 
 #if @BIGENDIAN@