package/gcc: fix ICE on xtensa, PR target/82181

package/gcc: fix ICE on xtensa, PR target/82181

Memory references to DI mode objects could incorrectly be created at
offsets that are not supported by instructions l32i/s32i, resulting in
ICE at a stage when access to the object is split into access to its
subwords:
  drivers/staging/rtl8188eu/core/rtw_ap.c:445:1:
     internal compiler error: in change_address_1, at emit-rtl.c:2126

Fixes: https://lkml.org/lkml/2017/9/10/151
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>