[patch, fortran] Improve dependency checking

[Thomas Koenig]

Hello world,

the attached pach does some more work in gfc_check_dependency for
the case where an identity between arguments would also lead
to problems.

It does not lead to removal of the warning with -Warray-temporaries,
because that is still generated by the call to library function.
Instead, I checked for the names of the variables which used to
be introduced by the matmul inlining code.

Regression-tested. OK for trunk?

Regards

	Thomas

2019-07-25  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/65819
	* dependency.h (gfc_dep_resovler): Add optional argument identical.
	* dependency.c (gfc_check_dependency): Do not alway return 1 if
	the symbol is the same. Pass on identical to gfc_dep_resolver.
	(gfc_check_element_vs_element): Whitespace fix.
	(gfc_dep_resolver): Adjust comment for function.  If identical is
	true, return 1 if any overlap has been found.

2019-07-25  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/65819
	* gfortran.dg/dependency_54.f90: New test.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: p1.diff
Type: text/x-patch
Size: 3792 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/fortran/attachments/20190725/550ab3ea/attachment.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: dependency_54.f90
Type: text/x-fortran
Size: 864 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/fortran/attachments/20190725/550ab3ea/attachment-0001.bin>