How to change bit-field allocation

[Robert Dewar]

Min ZOU wrote:
> Thanks a lot for your help!
> 
> BTW, I found in the latest Renesas SH proprietary compiler, there is 
> already an option to change the default bit-field allocation so that 
> bit-field's members are allocated from the lower bit, which is same as GCC.

It seems fundamental to me that bit fields must be allocated in a
manner consistent with the processor addressing, or you can get
non-contiguous fields.