Update section 11.5 (differences between ocamlopt and ocamlc)
Update section 11.5 (differences between ocamlopt and ocamlc)

Discuss FMA and also the issue from MPR#7271.

gerdstolpmann/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml,gerdstolpmann/ocaml