[flang] Error recovery in bad specific MIN/MAX calls

When a specific MIN/MAX intrinsic function (e.g. MAX1) reference
has an actual argument error, ensure that a later attempt to fold
the call into a constant doesn't crash due to a missing argument.
Fixes https://github.com/llvm/llvm-project/issues/63140

Differential Revision: https://reviews.llvm.org/D153470