Minor improvement to H8 startup code

[Jeff Law]

On 12/30/23 14:46, Jeff Johnston wrote:
> Ok.  Can we call this one the last for snapshot?  I would like to do the 
> snapshot before Jan 1st.
Sure.  I've only got one more target dependent change I'm carrying for 
libgloss c99/gcc-14.  There's still some generic newlib stuff for 
c99/gcc-14, but I think we can trickle those in after the snapshot. 
The fixes should only affect building with the unreleased gcc-14.

Jeff