faster Float32 to Int64 itrunc

adds a type argument fptosi(T, x). most other similar intrinsics
already have this argument.

support more types in eqfsi and eqfui. however all-64-bit is faster
than using mixed sizes, so this is mostly cosmetic, but makes the
intrinsics easier to use.

helps #7076 if itrunc is used
Merge branch 'master' of github.com:JuliaLang/julia