[Bug fortran/53077] suggestion to add the .f extension to the list of file extensions that trigger enabling of the preprocessor

[slayoo at staszic dot waw.pl]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53077

--- Comment #1 from Sylwester Arabas <slayoo at staszic dot waw.pl> 2012-04-22 
20:35:49 UTC ---
The gfortran-mp-4.6 vs. gfortran difference in the code above is not relevant
to the issue.