Fix ModRM parsing
Fix ModRM parsing

Index/Base needs to be extended by REX bits before checking for specific
values (e.g. index 4 == no indexing).

Also add a specific instruction result width "VT_Implicit" for
pass-through instructions, which prohibits automatic REX width bit
generation (32 vs. 64 bit).

lrr-tum/dbrew,lrr-tum/dbrew,lrr-tum/dbrew,lrr-tum/dbrew,lrr-tum/dbrew