Implement -e trace=%stat option

Implement -e trace=%stat option

linux/*/syscallent*.h part is updated automatically by:

    sed -i '/statx/! s/TF|TSTA,/TF|TST|TSTA,/' linux/*/syscallent*.h

* sysent.h (TRACE_STAT): New macro.
* syscall.c: Alias LST to TRACE_STAT around syscallent.h inclusion.
* qualify.c (lookup_class): Add TRACE_STAT for "%stat".
* strace.1 (.SS Filtering): Add information about %stat syscall class.
* NEWS: Mention this change.
* linux/aarch64/syscallent.h (stat): Add TST flag.
* linux/ia64/syscallent.h: Likewise.
* linux/mips/syscallent-n32.h: Likewise.
* linux/mips/syscallent-n64.h: Likewise.
* linux/s390x/syscallent.h: Likewise.
* linux/x32/syscallent.h: Likewise.
* linux/x86_64/syscallent.h: Likewise.
* linux/arm/syscallent.h (oldstat, stat, stat64): Likewise.
* linux/bfin/syscallent.h: Likewise.
* linux/crisv10/syscallent.h: Likewise.
* linux/i386/syscallent.h: Likewise.
* linux/m68k/syscallent.h: Likewise.
* linux/microblaze/syscallent.h: Likewise.
* linux/mips/syscallent-o32.h: Likewise.
* linux/powerpc/syscallent.h: Likewise.
* linux/sh64/syscallent.h: Likewise.
* linux/sh/syscallent.h: Likewise.
* linux/avr32/syscallent.h (stat, stat64): Likewise.
* linux/hppa/syscallent.h: Likewise.
* linux/s390/syscallent.h: Likewise.
* linux/sparc64/syscallent.h: Likewise.
* linux/sparc/syscallent.h: Likewise.
* linux/xtensa/syscallent.h: Likewise.
* linux/powerpc64/syscallent.h (oldstat, stat): Likewise.
* linux/alpha/syscallent.h (osf_old_stat, osf_stat, stat, stat64): Likewise.
* linux/mips/syscallent-compat.h (bsd43_oldstat, bsd43_stat, posix_stat,
svr4_stat, svr4_xstat, sysv_stat, sysv_xstat): Likewise.
* tests/gen_tests.in (trace_stat): New entry.
* tests/trace_stat.in: New file.
* tests/Makefile.am (EXTRA_DIST): Add it.
* tests/ksysent.c (TST): New macro, defined to 0.
* tests/nsyscalls.c: Likewise.