Makefile.SH: treat Solaris on Gentoo Prefix as having soname versioning

sunos target exists, but doesn't use -L. in linklibperl which we also
require, so make solaris be treated as *bsd

Signed-off-by: Fabian Groffen <grobian@gentoo.org>

--- a/Makefile.SH
+++ b/Makefile.SH
@@ -88,7 +88,7 @@
 		linklibperl="-lperl"
 		shrpldflags="$shrpldflags -Wl,-soname -Wl,libperl.so.${revision}.${patchlevel}"
 		;;
-	netbsd*|freebsd*|openbsd*|dragonfly*|bitrig*)
+	netbsd*|freebsd*|openbsd*|dragonfly*|bitrig*|solaris*)
 		linklibperl="-L. -lperl"
 		shrpldflags="$shrpldflags -Wl,-soname -Wl,libperl.so.${revision}.${patchlevel}"
 		;;