include/dis-asm.h patch for cgen disassemblers

[Andrew Cagney]

> For the benefit of mystified binutils/cgen readers, I think the
> reason cagney is so interested in the first column, is a
> long-standing quixotic battle against gdb-ically incorrect
> bfd modelling.  Apparently, roughly speaking, gdb's multiarch
> system likes to map from bfd_arch numbers (and not bfd_arch/bfd_mach
> pairs) to a vector of target-specific functions.  Using multiple
> bfd_mach codes for dissimilar family members throws a monkey-wrench
> into this scheme, for the simpleminded "each bfd_mach is a strict
> subtype of the bfd_arch" view of the world.


No, your wrong.

It is certainly in GDB's best interest to get a consistent ISA et.al. 
model in place, however the form of that model is open to negotiation 
(just like everything else).  I'd have thought, though, that this 
objective wasn't just for GDB.  Rather it is equally shared by BINUTILS. 
I would hope that we (FSF toolchain developers) want to see consistency 
both across tool chains and between binutils and GDB.

Remember, even without GDB, this problem exists.  Assemblers and 
disassemblers hit this all the time - each one doing it differently 
because there is zero guidance.

Andrew