Fix #2410: Invalid offsets are accepted
Fix #2410: Invalid offsets are accepted

.NET :   0 failing
Fable:  64 failing

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