[Bug fortran/70330] [5 Regression] ICE with -Wextra -Wno-unused-dummy-argument and unused optional dummy argument

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70330

Dominique d'Humieres <dominiq at lps dot ens.fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-03-21
            Summary|REGRESSION: ICE with        |[5 Regression] ICE with
                   |-Wextra                     |-Wextra
                   |-Wno-unused-dummy-argument  |-Wno-unused-dummy-argument
                   |and unused optional dummy   |and unused optional dummy
                   |argument                    |argument
     Ever confirmed|0                           |1

--- Comment #1 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
The ICE disappeared between revisions r225099 (2015-06-27, ICE) and r225554
(2015-07-08, warning only).

Note that 4.9.3 gives

pr70330.f90:1:

function f(o)
1
Warning: Return value of function 'f' at (1) not set
pr70330.f90:1:0: warning: unused parameter 'o' [-Wunused-parameter]
 function f(o)
 ^

The change occurred between revisions r217100 (2014-11-04, warnings) and
r217500 (2014-11-13, ICE), so it is a regression for the gcc5 branch.