Improve function body compilation
Improve function body compilation

ncave/Fable,fable-compiler/Fable,inosik/Fable,ncave/Fable,fable-compiler/Fable,inosik/Fable,ncave/Fable,fable-compiler/Fable,ncave/Fable,ncave/Fable,fable-compiler/Fable,fable-compiler/Fable,fable-compiler/Fable,ncave/Fable,fable-compiler/Fable,ncave/Fable