Fix byte encoding macros.

src/google/protobuf/io/coded_stream.h

@@ -782,8 +782,7 @@ inline const uint8* CodedInputStream::ReadLittleEndian64FromArray(
 }
 
 inline bool CodedInputStream::ReadLittleEndian32(uint32* value) {
-#if !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST) && \
-    defined(__BYTE_ORDER) && __BYTE_ORDER == __LITTLE_ENDIAN
+#if defined(PROTOBUF_LITTLE_ENDIAN)
   if (GOOGLE_PREDICT_TRUE(BufferSize() >= static_cast<int>(sizeof(*value)))) {
     memcpy(value, buffer_, sizeof(*value));
     Advance(sizeof(*value));
@@ -797,8 +796,7 @@ inline bool CodedInputStream::ReadLittleEndian32(uint32* value) {
 }
 
 inline bool CodedInputStream::ReadLittleEndian64(uint64* value) {
-#if !defined(PROTOBUF_DISABLE_LITTLE_ENDIAN_OPT_FOR_TEST) && \
-    defined(__BYTE_ORDER) && __BYTE_ORDER == __LITTLE_ENDIAN
+#if defined(PROTOBUF_LITTLE_ENDIAN)
   if (GOOGLE_PREDICT_TRUE(BufferSize() >= static_cast<int>(sizeof(*value)))) {
     memcpy(value, buffer_, sizeof(*value));
     Advance(sizeof(*value));