xz: Use CRC32

This reverts c475924d6d.

Update #2909.
Close #2994.

cpukit/libmisc/Makefile.am

@@ -195,7 +195,7 @@ libuuid_a_SOURCES = uuid/clear.c uuid/compare.c uuid/copy.c uuid/gen_uuid.c \
 
 ## xz-embedded
 noinst_LIBRARIES += libxz.a
-libxz_a_SOURCES = xz/xz/h xz/xz_crc32.c xz/xz_crc64.c \
+libxz_a_SOURCES = xz/xz/h xz/xz_crc32.c \
 	xz/xz_dec_lzma2.c xz/xz_dec_stream.c
 
 EXTRA_DIST += xz/README xz/COPING

cpukit/libmisc/xz/xz_config.h

@@ -11,7 +11,7 @@
 #define XZ_CONFIG_H
 
 /* Uncomment to enable CRC64 support. */
-#define XZ_USE_CRC64
+/* #define XZ_USE_CRC64 */
 
 /* Uncomment as needed to enable BCJ filter decoders. */
 /* #define XZ_DEC_X86 */
@@ -62,10 +62,6 @@ typedef unsigned char bool;
  * NOTE: System headers on GNU/Linux may #define this macro already,
  * so if you want to change it, you need to #undef it first.
  */
-#ifdef __rtems__
-#	undef __always_inline
-#	define __always_inline inline
-#else
 #ifndef __always_inline
 #	ifdef __GNUC__
 #		define __always_inline \
@@ -74,7 +70,6 @@ typedef unsigned char bool;
 #		define __always_inline inline
 #	endif
 #endif
-#endif
 
 /* Inline functions to access unaligned unsigned 32-bit integers */
 #ifndef get_unaligned_le32