rdatawad: handle big-endian hosts again. (#707)

Removing config.h from .c files meant WORDS_BIGENDIAN was always not
defined when rd_util.h was included.

This adds it back, restoring support for big-endian hosts.

Author: FtZPetruska

prboom2/data/CMakeLists.txt

@@ -38,6 +38,14 @@ include(DsdaTargetFeatures)
 dsda_target_set_warnings(dsda_rdatawad)
 dsda_target_silence_deprecation(dsda_rdatawad)
 
+include(CheckBigEndian)
+check_big_endian(RD_IS_BIG_ENDIAN)
+
+target_compile_definitions(dsda_rdatawad
+    PRIVATE
+    "RD_IS_BIG_ENDIAN=${RD_IS_BIG_ENDIAN}"
+)
+
 # PrBoom-Plus internal WAD
 
 set(PALETTE

prboom2/data/rd_util.h

@@ -9,7 +9,7 @@
 #define ATTR(x)
 #endif
 
-#ifdef WORDS_BIGENDIAN
+#if RD_IS_BIG_ENDIAN
 # ifdef __GNUC__
 #define LONG(x) __builtin_bswap32((x))
 #define SHORT(x) (__builtin_bswap32((x))>>16)