crucible: MAP_32BIT is not defined on ARM

Also fix a stray #if that should be #ifdef.

Closes:  https://github.com/Zygo/bees/issues/59

Signed-off-by: Zygo Blaxell <bees@furryterror.org>

lib/fd.cc

@@ -174,11 +174,13 @@ namespace crucible {
 	static const struct bits_ntoa_table mmap_flags_table[] = {
 		NTOA_TABLE_ENTRY_BITS(MAP_SHARED),
 		NTOA_TABLE_ENTRY_BITS(MAP_PRIVATE),
+#ifdef MAP_32BIT
 		NTOA_TABLE_ENTRY_BITS(MAP_32BIT),
+#endif
 		NTOA_TABLE_ENTRY_BITS(MAP_ANONYMOUS),
 		NTOA_TABLE_ENTRY_BITS(MAP_DENYWRITE),
 		NTOA_TABLE_ENTRY_BITS(MAP_EXECUTABLE),
-#if MAP_FILE
+#ifdef MAP_FILE
 		NTOA_TABLE_ENTRY_BITS(MAP_FILE),
 #endif
 		NTOA_TABLE_ENTRY_BITS(MAP_FIXED),