[Bug inline-asm/97708] Inline asm does not use the local register asm specified with register ... asm() as input

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97708

--- Comment #29 from Segher Boessenkool <segher at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #26)
> So it would need to be diagnosed in the FE (only), making a + 0 valid and
> a not.  Eh.

We do not *have* to diagnose anything, certainly not things that just
happen to work (if "a+0" is optimised to just "a", say).  But it would
be good if we could diagnose the obvious and certainly wrong cases we
do not do now -- like a register asm that does not match the operand
constraint!