Fake up enough headers to let libstddjb selfpipe build

Signed-off-by: Anders Kaseorg <andersk@mit.edu>

third/libstddjb/djbunix.h

@@ -0,0 +1,17 @@
+/* ISC license. */
+
+#ifndef DJBUNIX_H
+#define DJBUNIX_H
+
+#define DJBUNIX_FLAG_NB  0x01U
+#define DJBUNIX_FLAG_COE 0x02U
+
+extern int coe (int) ;
+extern int ndelay_on (int) ;
+extern int pipe_internal (int *, unsigned int) ;
+#define pipenb(p) pipe_internal(p, DJBUNIX_FLAG_NB)
+#define pipecoe(p) pipe_internal(p, DJBUNIX_FLAG_COE)
+#define pipenbcoe(p) pipe_internal(p, DJBUNIX_FLAG_NB|DJBUNIX_FLAG_COE)
+extern int fd_close (int) ;
+
+#endif

third/libstddjb/error.h

@@ -0,0 +1,14 @@
+/* ISC license. */
+
+#ifndef ERROR_H
+#define ERROR_H
+
+#include <errno.h>
+#include "gccattributes.h"
+
+extern char const *error_str (int) gccattr_const ;
+extern int error_temp (int) gccattr_const ;
+
+#define error_isagain(e) (((e) == EAGAIN) || ((e) == EWOULDBLOCK))
+
+#endif

third/libstddjb/sysdeps.h

@@ -0,0 +1,24 @@
+#ifndef SYSDEPS_H
+#define SYSDEPS_H
+
+#include "config.h"
+
+#ifdef HAVE_PIPE2
+#define HASPIPE2
+#else
+#undef HASPIPE2
+#endif
+
+#ifdef HAVE_SIGNALFD
+#define HASSIGNALFD
+#else
+#undef HASSIGNALFD
+#endif
+
+#ifdef HAVE_SIGACTION
+#define HASSIGACTION
+#else
+#undef HASSIGACTION
+#endif
+
+#endif

third/libstddjb/uint64.h

@@ -0,0 +1,7 @@
+#ifndef UINT64_H
+#define UINT64_H
+
+#include <stdint.h>
+typedef uint64_t uint64;
+
+#endif