Rust: Add back endianness check via Linux endian.h for old GCC on MIPS

Author: angelsl

lib/builtins/int_endianness.h

@@ -105,6 +105,19 @@
 
 #endif /* Windows */
 
+#if defined(__linux__)
+#include <endian.h>
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define _YUGA_LITTLE_ENDIAN 0
+#define _YUGA_BIG_ENDIAN    1
+#elif __BYTE_ORDER == __LITTLE_ENDIAN
+#define _YUGA_LITTLE_ENDIAN 1
+#define _YUGA_BIG_ENDIAN    0
+#endif /* __BYTE_ORDER */
+
+#endif /* GNU/Linux */
+
 #endif /* Clang or GCC. */
 
 /* . */