Add a sanity test of x86 insn decoder against a stream
of randomly generated input, at build time.

This test is also able to reproduce any bug that might
trigger by allowing the passing of random-seed and
iteration-number to the test, or by passing input
which has invalid byte code.

Changes in V2:
 - Code cleanup.
 - Show how to reproduce the error by insn_sanity test.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: acme@redhat.com
Cc: ming.m.lin@intel.com
Cc: robert.richter@amd.com
Cc: ravitillo@lbl.gov
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20111020140109.20938.92572.stgit@localhost.localdomainSigned-off-by: Ingo Molnar <mingo@elte.hu>