Stop decoding in drmgr_decode_sysnum_from_wrapper() on an OP_ret instruction to avoid incorrect wrapper analysis.  This is prone to happen on kernel32 routines which on different flavors of Windows vary in whether they actually make a system call.  This bug was hit on Win8 kernel32!VerifyConsoleIoHandle.
Stop decoding in drmgr_decode_sysnum_from_wrapper() on an OP_ret
instruction to avoid incorrect wrapper analysis.  This is prone to
happen on kernel32 routines which on different flavors of Windows vary
in whether they actually make a system call.  This bug was hit on Win8
kernel32!VerifyConsoleIoHandle.

git-svn-id: ed337ca7cdb08c0ba29d8fe58632bb7686892c2d@1934 49cc7528-f6fd-11dd-9d1a-b59b2e1864b6

rnk/dynamorio,rnk/dynamorio,rnk/dynamorio,rnk/dynamorio,rnk/dynamorio