Fix Fortran st_size fields of mpi_fortran_argv_null_, mpi_fortran_weights_empty_, mpi_fortran_unweighted_, mpi_fortran_errcodes_ignore_, and mpi_fortran_argvs_null_

Due to a GNU ld bug (https://sourceware.org/bugzilla/show_bug.cgi?id=25236),
the 5 common symbols are incorrectly versioned VER_NDX_LOCAL
because their definitions in Fortran sources have smaller st_size than
those in libmpi.so.

This makes the Fortran library not linkable with lld in distributions
that ship openmpi built with -Wl,--version-script
(https://bugs.llvm.org/show_bug.cgi?id=43748):

  % mpifort -fuse-ld=lld /dev/null
  ld.lld: error: corrupt input file: version definition index 0 for symbol
  mpi_fortran_argv_null_ is out of bounds
  >>> defined in /usr/lib/x86_64-linux-gnu/openmpi/lib/libmpi_usempif08.so
  ...

Work around it by changing dimensions so that st_size of Fortran sources
are at least as large as those in libmpi.so (equal on 64-bit platforms).

This also fixes a minor issue that MPI_UNWEIGHTED and
MPI_WEIGHTS_EMPTY were not declared as arrays (not fully fixed by commit
107c007).

Fixes #7209

Signed-off-by: Fangrui Song <[email protected]>

Author: MaskRay

ompi/mpi/fortran/base/gen-mpi-mangling.pl

@@ -64,33 +64,33 @@
 $fortran->{unweighted} = {
     c_type => "int *",
     c_name => "mpi_fortran_unweighted",
-    f_type => "integer",
+    f_type => "integer, dimension(2)",
     f_name => "MPI_UNWEIGHTED",
 };
 $fortran->{weights_empty} = {
     c_type => "int *",
     c_name => "mpi_fortran_weights_empty",
-    f_type => "integer",
+    f_type => "integer, dimension(2)",
     f_name => "MPI_WEIGHTS_EMPTY",
 };
 
 $fortran->{argv_null} = {
     c_type => "char *",
     c_name => "mpi_fortran_argv_null",
-    f_type => "character, dimension(1)",
+    f_type => "character, dimension(8)",
     f_name => "MPI_ARGV_NULL",
 };
 $fortran->{argvs_null} = {
     c_type => "char *",
     c_name => "mpi_fortran_argvs_null",
-    f_type => "character, dimension(1, 1)",
+    f_type => "character, dimension(1, 8)",
     f_name => "MPI_ARGVS_NULL",
 };
 
 $fortran->{errcodes_ignore} = {
     c_type => "int *",
     c_name => "mpi_fortran_errcodes_ignore",
-    f_type => "integer, dimension(1)",
+    f_type => "integer, dimension(2)",
     f_name => "MPI_ERRCODES_IGNORE",
 };
 $fortran->{status_ignore} = {