unxz: new applet, complete with xzcat and xz -d aliases

function                                             old     new   delta
unpack_xz_stream_stdin                                 -    3953   +3953
lzma_main                                              -    2601   +2601
lzma_len                                               -     516    +516
dec_vli                                                -     165    +165
dict_repeat                                            -     103    +103
lzma_reset                                             -      98     +98
fill_temp                                              -      98     +98
crc32_validate                                         -      93     +93
xz_dec_reset                                           -      77     +77
unxz_main                                              -      77     +77
index_update                                           -      47     +47
xz_crc32                                               -      40     +40
packed_usage                                       27044   27060     +16
make_new_name_unxz                                     -      14     +14
applet_names                                        2240    2254     +14
applet_main                                         1312    1324     +12
applet_nameofs                                       656     662      +6
unpack_unxz                                            -       5      +5
send_tree                                            355     360      +5
applet_install_loc                                   164     166      +2
------------------------------------------------------------------------------
(add/remove: 15/0 grow/shrink: 6/0 up/down: 7942/0)          Total: 7942 bytes
   text    data     bss     dec     hex filename
 844032     453    6812  851297   cfd61 busybox_old
 852063     453    6812  859328   d1cc0 busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/archival/libunarchive/unxz/xz_config.h b/archival/libunarchive/unxz/xz_config.h
new file mode 100644
index 0000000..3259815
--- /dev/null
+++ b/archival/libunarchive/unxz/xz_config.h
@@ -0,0 +1,119 @@
+/*
+ * Private includes and definitions for userspace use of XZ Embedded
+ *
+ * Author: Lasse Collin <lasse.collin@tukaani.org>
+ *
+ * This file has been put into the public domain.
+ * You can do whatever you want with this file.
+ */
+
+#ifndef XZ_CONFIG_H
+#define XZ_CONFIG_H
+
+/* Uncomment as needed to enable BCJ filter decoders. */
+/* #define XZ_DEC_X86 */
+/* #define XZ_DEC_POWERPC */
+/* #define XZ_DEC_IA64 */
+/* #define XZ_DEC_ARM */
+/* #define XZ_DEC_ARMTHUMB */
+/* #define XZ_DEC_SPARC */
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "xz.h"
+
+#define kmalloc(size, flags) malloc(size)
+#define kfree(ptr) free(ptr)
+#define vmalloc(size) malloc(size)
+#define vfree(ptr) free(ptr)
+
+#define memeq(a, b, size) (memcmp(a, b, size) == 0)
+#define memzero(buf, size) memset(buf, 0, size)
+
+#define min(x, y) ((x) < (y) ? (x) : (y))
+#define min_t(type, x, y) min(x, y)
+
+/*
+ * Some functions have been marked with __always_inline to keep the
+ * performance reasonable even when the compiler is optimizing for
+ * small code size. You may be able to save a few bytes by #defining
+ * __always_inline to plain inline, but don't complain if the code
+ * becomes slow.
+ *
+ * NOTE: System headers on GNU/Linux may #define this macro already,
+ * so if you want to change it, it you need to #undef it first.
+ */
+#ifndef __always_inline
+#	ifdef __GNUC__
+#		define __always_inline \
+			inline __attribute__((__always_inline__))
+#	else
+#		define __always_inline inline
+#	endif
+#endif
+
+/*
+ * Some functions are marked to never be inlined to reduce stack usage.
+ * If you don't care about stack usage, you may want to modify this so
+ * that noinline_for_stack is #defined to be empty even when using GCC.
+ * Doing so may save a few bytes in binary size.
+ */
+#ifndef noinline_for_stack
+#	ifdef __GNUC__
+#		define noinline_for_stack __attribute__((__noinline__))
+#	else
+#		define noinline_for_stack
+#	endif
+#endif
+
+/* Inline functions to access unaligned unsigned 32-bit integers */
+#ifndef get_unaligned_le32
+static inline uint32_t XZ_FUNC get_unaligned_le32(const uint8_t *buf)
+{
+	return (uint32_t)buf[0]
+			| ((uint32_t)buf[1] << 8)
+			| ((uint32_t)buf[2] << 16)
+			| ((uint32_t)buf[3] << 24);
+}
+#endif
+
+#ifndef get_unaligned_be32
+static inline uint32_t XZ_FUNC get_unaligned_be32(const uint8_t *buf)
+{
+	return (uint32_t)(buf[0] << 24)
+			| ((uint32_t)buf[1] << 16)
+			| ((uint32_t)buf[2] << 8)
+			| (uint32_t)buf[3];
+}
+#endif
+
+#ifndef put_unaligned_le32
+static inline void XZ_FUNC put_unaligned_le32(uint32_t val, uint8_t *buf)
+{
+	buf[0] = (uint8_t)val;
+	buf[1] = (uint8_t)(val >> 8);
+	buf[2] = (uint8_t)(val >> 16);
+	buf[3] = (uint8_t)(val >> 24);
+}
+#endif
+
+#ifndef put_unaligned_be32
+static inline void XZ_FUNC put_unaligned_be32(uint32_t val, uint8_t *buf)
+{
+	buf[0] = (uint8_t)(val >> 24);
+	buf[1] = (uint8_t)(val >> 16);
+	buf[2] = (uint8_t)(val >> 8);
+	buf[3] = (uint8_t)val;
+}
+#endif
+
+/*
+ * Use get_unaligned_le32() also for aligned access for simplicity. On
+ * little endian systems, #define get_le32(ptr) (*(const uint32_t *)(ptr))
+ * could save a few bytes in code size.
+ */
+#define get_le32 get_unaligned_le32
+
+#endif