deps: ntlmclient: provide platform-independent htonll implementation

With the introduction of ntlmclient, we've started playing whac-a-mole
with platforms to support the non-standard htonll function. Let's end
this game once and for all by providing a generic implementation that's
implemented via htonl(3P) and a endianness-check in CMake.

deps/ntlmclient/CMakeLists.txt

@@ -1,10 +1,17 @@
+INCLUDE(TestBigEndian)
+
 FILE(GLOB SRC_NTLMCLIENT "ntlm.c" "unicode_builtin.c" "util.c")
 LIST(SORT SRC_NTLMCLIENT)
 
 ADD_DEFINITIONS(-DNTLM_STATIC=1)
 
 DISABLE_WARNINGS(implicit-fallthrough)
 
+TEST_BIG_ENDIAN(BIG_ENDIAN)
+IF(BIG_ENDIAN)
+	ADD_DEFINITIONS(-DBIG_ENDIAN)
+ENDIF()
+
 IF(USE_HTTPS STREQUAL "SecureTransport")
 	ADD_DEFINITIONS(-DCRYPT_COMMONCRYPTO)
 	SET(SRC_NTLMCLIENT_CRYPTO "crypt_commoncrypto.c")

deps/ntlmclient/compat.h

@@ -21,31 +21,10 @@
 # include <stdbool.h>
 #endif
 
-#ifdef __linux__
-/* See man page endian(3) */
-# include <endian.h>
-# define htonll htobe64
-#elif defined(__NetBSD__) || defined(__OpenBSD__)
-/* See man page htobe64(3) */
-# include <endian.h>
-# define htonll htobe64
-#elif defined(__FreeBSD__)
-/* See man page bwaps64(9) */
-# include <sys/endian.h>
-# define htonll htobe64
-#elif defined(sun) || defined(__sun)
-/* See man page byteorder(3SOCKET) */
-# include <sys/types.h>
-# include <netinet/in.h>
-# include <inttypes.h>
-
-# if !defined(htonll)
-#  if defined(_BIG_ENDIAN)
-#   define htonll(x) (x)
-#  else
-#   define htonll(x) ((((uint64_t)htonl(x)) << 32) + htonl((uint64_t)(x) >> 32))
-#  endif
-# endif
+#if defined(BIG_ENDIAN)
+# define htonll(x) (x)
+#else
+# define htonll(x) ((((uint64_t)htonl(x)) << 32) + htonl((uint64_t)(x) >> 32))
 #endif
 
 #ifndef MIN