Consolidate code to compute sin and cos from lookup tables

Consolidate code to compute sin and cos from lookup tables

This patch consolidates the multiple copies of code that looks up sin
and cos of a number from the lookup table and computes the final
value, into static functions.  This does not have a noticeable
performance impact since the functions are inlined by gcc.

There is further scope for consolidation in the functions but they
cause a more noticable impact on performance (>5%) due to which I have
held back on them.