Index: gcc-5/src/gcc/config/i386/t-sol2
===================================================================
--- gcc-5.orig/src/gcc/config/i386/t-sol2
+++ gcc-5/src/gcc/config/i386/t-sol2
@@ -16,6 +16,7 @@
 # along with GCC; see the file COPYING3.  If not see
 # <http://www.gnu.org/licenses/>.
 
-MULTILIB_OPTIONS = m32/m64
-MULTILIB_DIRNAMES = 32 amd64
-MULTILIB_OSDIRNAMES = . amd64
+MULTILIB_OPTIONS = m64/m32
+MULTILIB_DIRNAMES = 64 32
+MULTILIB_OSDIRNAMES = m64=../lib$(call if_multiarch,:x86_64-illumos)
+MULTILIB_OSDIRNAMES+= m32=$(if $(wildcard $(shell echo $(SYSTEM_HEADER_DIR))/../../usr/lib32),../lib32,../lib)$(call if_multiarch,:i386-illumos)