dev-python/pypy-bin: Improve binary package deps

Add subslots whenever possible, remove useless slot from sys-libs/glibc
and add missing dep on sys-devel/gcc (for libgcc_s.so).

dev-python/pypy-bin/pypy-bin-5.9.0-r1.ebuild

@@ -37,15 +37,15 @@ SLOT="0/41"
 KEYWORDS="~amd64 ~x86"
 IUSE="doc gdbm +jit sqlite cpu_flags_x86_sse2 test tk"
 
-# yep, world would be easier if people started filling subslots...
 RDEPEND="
-	app-arch/bzip2:0=
-	dev-libs/expat:0=
-	dev-libs/libffi:0=
-	dev-libs/openssl:0=[-bindist]
-	sys-libs/glibc:2.2=
+	app-arch/bzip2:0/1
+	dev-libs/expat:0/0
+	dev-libs/libffi:0/0
+	dev-libs/openssl:0/0[-bindist]
+	sys-devel/gcc:*
+	sys-libs/glibc
 	sys-libs/ncurses:0/6
-	sys-libs/zlib:0=
+	sys-libs/zlib:0/1
 	gdbm? ( sys-libs/gdbm:0= )
 	sqlite? ( dev-db/sqlite:3= )
 	tk? (