Change the continuation line format for stat.h, debug.h
AOCC flang compiler is complaining about the continuation lines in these
two files. It does not complain about similar continuation lines in
files (e.g. SRC/icbacn.F90), so I believe this is due to flang setting
the Fortran dialect to something like F77 for most of the compilations,
which cause problems with these *.h files.
I cannot find a way to force flang Fortran dialect to accept the & at
end of line continuation marker, so this patch changes the continuation
lines in these two files (stat.h, debug.h) to use continuation marker in
column 6.
This should fix#300
