[Bug target/95646] arm-none-eabi function attribute 'cmse_nonsecure_entry' wipes register values with -Os

[avieira at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95646

avieira at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2020-06-15
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from avieira at gcc dot gnu.org ---
Reproduced and confirmed.  This is because we special treat HI_REGS in Thumb-1
when optimizing for size.  I have a fix ready, just doing some testing.