Use --match-full-lines to make sure that FileCheck doesn't match the
output against the CHECK lines (which, like other comments, are also
printed).
More specifically, we want to make sure that the following check in the
input file:
! CHECK: <some-fortran-input>
is matched by FileCheck with <some-fortran-input> in the generated
output. Without --match-full-lines, that check-line will be matched
with !CHECK: <some-fortran-input> instead (which is also
printed together with other contents of the file).
Adding --match-full-lines makes the tests stricter and this change
revealed that some checks were passing only because that flag was
missing. These are updated accordingly.