* gdb.fortran/array-element.exp: Use f90, not f77.
* gdb.fortran/complex.exp: Use f90, not f77.
* gdb.fortran/derived-type.exp: Use f90, not f77.
* gdb.fortran/library-module.exp: Use f90, not f77.
* gdb.fortran/logical.exp: Use f90, not f77.
* gdb.fortran/module.exp: Use f90, not f77.
* gdb.fortran/multi-dim.exp: Use f90, not f77.
* gdb.fortran/subarray.exp: Use f90, not f77.