Add an unpatched version of xz, XZ Utils, to /trunk/deps/third_party

xz/src/xz/hardware.h

+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       hardware.h
+/// \brief      Detection of available hardware resources
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+/// Initialize some hardware-specific variables, which are needed by other
+/// hardware_* functions.
+extern void hardware_init(void);
+
+
+/// Set custom value for maximum number of coder threads.
+extern void hardware_threadlimit_set(uint32_t threadlimit);
+
+/// Get the maximum number of coder threads. Some additional helper threads
+/// are allowed on top of this).
+extern uint32_t hardware_threadlimit_get(void);
+
+
+/// Set custom memory usage limit. This is used for both encoding and
+/// decoding. Zero indicates resetting the limit back to defaults.
+extern void hardware_memlimit_set(uint64_t memlimit);
+
+/// Set custom memory usage limit as a percentage of installed RAM.
+/// The percentage must be in the range [1, 100].
+extern void hardware_memlimit_set_percentage(uint32_t percentage);
+
+/// Get the current memory usage limit.
+extern uint64_t hardware_memlimit_get(void);