Non-standard, unusable code generated for MSMPI_NO_SAL

[olesenm]

Cross-compiling with mingw used to work, but fails with a newer mingw

x86_64-w64-mingw32-gcc (SUSE Linux) 9.2.0

The failure messages report this:

/path/msmpi/include/mpi.h:514:1: error: expected '=', ',', ';', 'asm' or
 '__attribute__' before 'MPI_Send'
 MPI_Send(
 ^~~~~~~~

This traces back to many, many attribute expansions that appear to be specific to the microsoft compiler. Older versions of Gcc silently ignored these attributes, but they are now flagged as errors.

What is the best fix for this?