Autoconf updates

Move machine/endian.h to endian.h, use AC_HEADER_RESOLV over individual
header checks, and include prerequisites for netinet/ip.h check.

include/Makefile.am

@@ -7,6 +7,7 @@ SUBDIRS = openssl
 noinst_HEADERS = pqueue.h
 noinst_HEADERS += compat/dirent.h
 noinst_HEADERS += compat/dirent_msvc.h
+noinst_HEADERS += compat/endian.h
 noinst_HEADERS += compat/err.h
 noinst_HEADERS += compat/fcntl.h
 noinst_HEADERS += compat/limits.h
@@ -26,8 +27,6 @@ noinst_HEADERS += compat/win32netcompat.h
 noinst_HEADERS += compat/arpa/inet.h
 noinst_HEADERS += compat/arpa/nameser.h
 
-noinst_HEADERS += compat/machine/endian.h
-
 noinst_HEADERS += compat/netinet/in.h
 noinst_HEADERS += compat/netinet/ip.h
 noinst_HEADERS += compat/netinet/tcp.h

include/compat/machine/endian.h → include/compat/endian.h

@@ -1,6 +1,6 @@
 /*
  * Public domain
- * machine/endian.h compatibility shim
+ * endian.h compatibility shim
  */
 
 #ifndef LIBCRYPTOCOMPAT_BYTE_ORDER_H_
@@ -22,7 +22,7 @@
 #endif
 
 #elif defined(HAVE_ENDIAN_H)
-#include <endian.h>
+#include_next <endian.h>
 
 #elif defined(__sun) || defined(_AIX) || defined(__hpux)
 #include <sys/types.h>
@@ -32,9 +32,6 @@
 #include <standards.h>
 #include <sys/endian.h>
 
-#else
-#include_next <machine/endian.h>
-
 #endif
 
 #ifndef __STRICT_ALIGNMENT

m4/check-libc.m4

@@ -1,7 +1,11 @@
 AC_DEFUN([CHECK_LIBC_COMPAT], [
 # Check for libc headers
-AC_CHECK_HEADERS([err.h readpassphrase.h])
-AC_CHECK_HEADERS([arpa/nameser.h endian.h netinet/ip.h resolv.h])
+AC_CHECK_HEADERS([endian.h err.h readpassphrase.h])
+AC_CHECK_HEADERS([netinet/ip.h], [], [],
+[#include <sys/types.h>
+#include <arpa/inet.h>
+])
+AC_HEADER_RESOLV
 # Check for general libc functions
 AC_CHECK_FUNCS([asprintf freezero memmem])
 AC_CHECK_FUNCS([readpassphrase reallocarray recallocarray])