[M16C-ELF] : Problem with double and float data types.

[DJ Delorie]

> This is to update you that we have tested "float" and "double" data
> type computations on m32c hardware (3DKM32C/85U) and found that it
> is working successfully.

Ok, thanks.  The m32c allows -32..+32 shifts so it wouldn't have this
particular problem.  I'll probably end up splitting the m16c and m32c
shift patterns, and perhaps adding a helper function for large m16c
shifts.