Apply Intel Advisor optimization recommendations:
- Add FORCEINLINE to polint for better inlining
- Add SIMD VECTORLENGTHFOR and UNROLL directives to fderivs,
fdderivs, symmetry_bd, and kodis functions
This improves vectorization efficiency of finite difference
computations.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>