[flang] RESHAPE(PAD=) can be arbitrary array rank

[klausler]

Summary

The "pad=" argument in the intrinsic function table entry for RESHAPE
has a Rank::Array constraint, and that would be fine if not for RESHAPE
already having an earlier argument that's Rank::Array. It's the only
intrinsic that has multiple Rank::Array arguments. The checking for
the Rank::Array constraint was enforcing that multiple occurrences
of it have the same rank in a call, and that's not appropriate.

flang/lib/Evaluate/intrinsics.cpp

         if (!arrayArg) {
           arrayArg = arg;
           arrayArgName = d.keyword;
-        } else {
-          argOk &= rank == arrayArg->Rank();
         }
         break;
       case Rank::coarray: