[Fortran] preprocessor of NAG compiler has limits

Some Fortran codebases actively uses `#include` preprocessor statements. Usually, it compiles nicely, however, preprocessor of NAG compiler has the following limits:

| Item | Limits |
| --- | --- |
| Maximum INCLUDE file nesting | 20 |
| Maximum number of INCLUDE file references per compilation | 2047 |

Then, one needs to adjust codebase to avoid this limitations.

It would be nice to check number of `#include` preprocessor statements and give warnings if their number exceeds NAG limits.

NAG compiler limits: https://support.nag.com/nagware/np/r72_doc/manual/compiler_2_7.html#LIMITS