Expand Fortran file-extension support

[huxs001]

The built-in Fortran extension table in src/discover/language.c currently recognizes only:

.f03
.f08
.f90
.f95

This misses several commonly used Fortran extensions, especially in scientific and HPC codebases.

Please expand the Fortran entries to include:

.f
.F
.for
.f77
.fpp
.f90
.f95
.f03
.f08

In particular, .F is important for preprocessed Fortran source files. For example, CP2K uses .F extensively in its source tree:

https://github.com/cp2k/cp2k/tree/master/src

The uppercase .F extension is intentional: in many Fortran build systems it distinguishes source files that are passed through the C preprocessor from ordinary .f/.f90 sources.

Requested change

Update the Fortran section of src/discover/language.c to recognize at least:

/* Fortran */
{".f",   CBM_LANG_FORTRAN},
{".F",   CBM_LANG_FORTRAN},
{".for", CBM_LANG_FORTRAN},
{".f77", CBM_LANG_FORTRAN},
{".fpp", CBM_LANG_FORTRAN},
{".f90", CBM_LANG_FORTRAN},
{".f95", CBM_LANG_FORTRAN},
{".f03", CBM_LANG_FORTRAN},
{".f08", CBM_LANG_FORTRAN},

Please also add or update tests covering these extensions.

Reference: CP2K source tree, which contains extensive use of preprocessed .F Fortran sources:

https://github.com/cp2k/cp2k/tree/master/src

[DeusData]

Thank you @huxs001. Confirmed on current main: the built-in Fortran table contains only .f03, .f08, .f90, and .f95. Extension matching uses strcmp, so uppercase .F must be listed explicitly and cannot be covered by lowercase .f.

Routed as a normal-priority language coverage enhancement under #592, including tests for the fixed-form and preprocessed suffixes you listed.