Use <endian.h> to determine endianness, instead of a complex and
incorrect list of architectures.

Index: src/physfs_lzmasdk.h
--- src/physfs_lzmasdk.h.orig
+++ src/physfs_lzmasdk.h
@@ -486,6 +486,7 @@ EXTERN_C_END
 #define __CPU_ARCH_H
 
 /*#include "7zTypes.h"*/
+#include <endian.h>
 
 EXTERN_C_BEGIN
 
@@ -537,33 +538,9 @@ MY_CPU_LE_UNALIGN means that CPU is LITTLE ENDIAN and 
 #define MY_CPU_IA64_LE
 #endif
 
-#if defined(MY_CPU_X86_OR_AMD64) \
-    || defined(MY_CPU_ARM_LE) \
-    || defined(MY_CPU_IA64_LE) \
-    || defined(__LITTLE_ENDIAN__) \
-    || defined(__ARMEL__) \
-    || defined(__THUMBEL__) \
-    || defined(__AARCH64EL__) \
-    || defined(__MIPSEL__) \
-    || defined(__MIPSEL) \
-    || defined(_MIPSEL) \
-    || defined(__BFIN__) \
-    || (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
+#if BYTE_ORDER == LITTLE_ENDIAN
   #define MY_CPU_LE
-#endif
-
-#if defined(__BIG_ENDIAN__) \
-    || defined(__ARMEB__) \
-    || defined(__THUMBEB__) \
-    || defined(__AARCH64EB__) \
-    || defined(__MIPSEB__) \
-    || defined(__MIPSEB) \
-    || defined(_MIPSEB) \
-    || defined(__m68k__) \
-    || defined(__s390__) \
-    || defined(__s390x__) \
-    || defined(__zarch__) \
-    || (defined(__BYTE_ORDER__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
+#elif BYTE_ORDER == BIG_ENDIAN
   #define MY_CPU_BE
 #endif