Explicitly set the binutils version on Linux CI to ensure native images build properly.

nirvdrum · nirvdrum · commit 330467abd4ba · 2019-06-25T10:43:49.000-04:00
diff --git a/ci.jsonnet b/ci.jsonnet
@@ -302,6 +302,7 @@ local part_definitions = {
         mercurial: ">=3.2.4",
         ruby: ">=2.1.0",
         llvm: "==3.8",
+        binutils: ">=2.30",
       },
     },
     darwin: {
