[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 (const ActualArgument * arg{actualForDummy[j]}) {
       case Rank::matrix:
         argOk = rank == 2;
         break;
       case Rank::array:
         argOk = rank > 0;
         if (!arrayArg) {
           arrayArg = arg;
           arrayArgName = d.keyword;
-        } else {
-          argOk &= rank == arrayArg->Rank();
         }
         break;
       case Rank::coarray:
         argOk = IsCoarray(*arg);
         if (!argOk) {
           messages.Say(
               "'coarray=' argument must have corank > 0 for intrinsic '%s'"_err_en_US,
               name);