YAXT

This release fixes the following bugs for the 0.12.x series of releases:

• The xt_redist_get_send_MPI_Datatype and xt_redist_get_recv_MPI_Datatype queries are supposed to return MPI_DATATYPE_NULL for ranks with which no communication in the respective direction occurs. In release 0.12.0 such calls produced a fatal run-time error instead. 0.12.1 restores the specified behavior.
• The nvfortran 26.x Fortran compiler injects new exported data symbols into the library, these are now
  explicitly ignored by the test suite check for exported symbols.
• There's a bug in nvfortran 26.1, 26.3 and 26.5, at least, in which temporary array pointers to different slices of a encompassing array, passed to MPI_GET_ADDRESS, yield incorrect address results.
• In a slight extension of unspecified behavior: Redist collections of a single redist now actually return the datatypes for the first (and only component) instead of producing a fatal error.
• This leads to a minor extension of the test suite for redists.