[flang] Implement legacy %VAL and %REF actual arguments (#70343)

Update evaluate::ActualArgument to propagate the %VAL and %REF markers
until lowering.
Semantic checks are added to %VAL to ensure the argument is a numerical
or logical scalar.

I did not push these markers into the characteristics because other
compilers do not complain about inconsistent usages (e.g. using %VAL in
a call on a procedure with an interface without VALUE dummies is not
flagged by any compilers I tested, and it is not an issue for lowering,
so I decided to stay simple here and minimize the footprint of these
legacy features).

Lowering retrieves these markers and does the right thing: pass %VAL in
registers and pass %REF by address without adding any extra arguments
for characters.

0 files changed, 0 insertions, 0 deletions