update dwarf2 asm unwind info [hppa64-*-* failures]

[Richard Henderson]

John David Anglin wrote:
>> I don't suppose the HP linker supports R_PARISC_SEGREL32 at
>> an unaligned address?  If so, you could fairly easily arrange
>> to use DW_EH_PE_textrel as the encoding for the function addrs.
> 
> Don't know but I doubt it.  I would expect the situation is the
> same as for ia64.
> 
> It is possible that pc-relative relocations might work if .eh_frame
> was read-only for hppa64.  I have checked and found that plabels can
> be in a read-only in both executables and shared libraries.  However,
> I'm still not sure that the EH processing will work for shared
> libraries.  Also, putting the EH data in a read-only section would
> probably break existing code.

I wasn't considering making the EH data read-only, I was only
considering reducing the number of dynamic relocations needed.

At present, the absolute addresses mean that you need dynamic
fixups for shared libraries, and for executables when the segments
used aren't what the static linker selected.  If segment-relative
relocations were used, you'd only have one dynamic relocation --
the one that records the base of the segment in
__register_frame_info_bases.


r~