perf unwind-libunwind: Make libunwind register reading cross platform Move the libunwind register to perf register mapping functions in arch/../util/unwind-libunwind.c into a new libunwind-arch directory. Rename the functions to __get_perf_regnum_for_unw_regnum_. Add untested ppc32 and s390 functions. Add a get_perf_regnum_for_unw_regnum function that takes an ELF machine as well as a register number and chooses the appropriate architecture implementation. Split the x86 and powerpc 32 and 64-bit implementations apart so that a single libunwind-.h header is included. Move the e_machine into the unwind_info struct to make it easier to pass. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Albert Ou Cc: Alexander Shishkin Cc: Alexandre Ghiti Cc: Andrew Jones Cc: Athira Rajeev Cc: Dapeng Mi Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Florian Fainelli Cc: Howard Chu Cc: Ingo Molnar Cc: James Clark Cc: Jiri Olsa Cc: John Garry Cc: Leo Yan Cc: Li Guan Cc: Namhyung Kim Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Zijlstra Cc: Shimin Guo Cc: Thomas Richter Cc: Tomas Glozar Cc: Will Deacon [ Map UNW_PPC32_NIP to PERF_REG_POWERPC_NIP like done for 64-bit, pointed out by a local sashiko ] Signed-off-by: Arnaldo Carvalho de Melo