[Bug fortran/95847] [9/10/11 Regression] Internal error when processing pFUnit generated files with --coverage

["kargl at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95847

--- Comment #6 from kargl at gcc dot gnu.org ---
(In reply to Martin Liška from comment #5)
> I can only confirm it's a Fortran issue.
> Can please anybody from Fortran folks take a look?

First, the caveat, the Fortran code in the attached
example is invalid so a compiler can to do whatever
it wants, including dying with an ICE.

Split the example code into a file with only the 
module (say, d.f90) and a file with only the
function foo_suite (say, e.f90).  I get

% gfcx -c --coverage d.f90
% gfcx -c --coverage e.f90

with no ICE.  It seems that the strengthen assumption in
the git commit gets confused on where function information
comes from.

Just a SWAG.  Likely, gfortran reads the newly created
'foo.mod' to get information about the subroutine sbr,
so gfortran simply records the location where it obtains
the information about sbr.  That then means the location
for sbr is set to the line 'use foo'.  Why --coverage
finds the `end subroutine` at line 4 then becomes a
mystery.

Uncompressing the module shows that no location information
is stored in a module.

% cat foo.mod | gunzip
GFORTRAN module version '15' created from d.f90
(() () () () () () () () () () () () () () () () () () () () () () () ()
() () ())
()
()
()
()
()
(2 'foo' 'foo' '' 1 ((MODULE UNKNOWN-INTENT UNKNOWN-PROC UNKNOWN UNKNOWN
0 0) () (UNKNOWN 0 0 0 0 UNKNOWN ()) 0 0 () () 0 () () () 0 0)
3 'sbr' 'foo' '' 1 ((PROCEDURE UNKNOWN-INTENT MODULE-PROC DECL UNKNOWN 0
0 SUBROUTINE IMPLICIT_PURE) () (UNKNOWN 0 0 0 0 UNKNOWN ()) 0 0 () () 0
() () () 0 0)
)
('foo' 0 2 'sbr' 0 3)

So, it seems the strengthened assumption isn't so strong.