add ez80sf to CRT

[ZERICO2005]

Adds ez80sf functions to CRT. The compiler does not emit any __fp* or __*fp functions yet (apart from ftoll and (u)lltof aliasing fptoll and (u)lltofp).

Notes:

• ftoll and (u)lltof now use ez80sf routines (which are smaller and faster than the C routines used previously).
• The intention is that the compiler will emit __f*/__*f for ti/zilog floats, and __fp*/__*fp for ez80sf floats.
• Currently dtof/ftod alias to dtofp/fptod.
• dcmpo and dcmpu are not implemented yet. But you can alias them to dcmp as a temporary fix should you need it.