Update version of Go to 1.5

mojo/go/rules.gni

Index: mojo/go/rules.gni
diff --git a/mojo/go/rules.gni b/mojo/go/rules.gni
index 328640575e3c24185fce14c4376c9bdba351e027..60714f0f088381de992ef2900567d747a55395de 100644
--- a/mojo/go/rules.gni
+++ b/mojo/go/rules.gni
@@ -137,11 +137,8 @@ template("go_mojo_application") {
       "-I" + rebase_path("//"),
       "-L" + rebase_path(target_out_dir) + " -l" + static_library_name + "",
       "build",
-      "-ldflags=-shared",
     ]
-    if (is_linux) {
-      args += [ "-buildmode=c-shared" ]
-    }
+    args += [ "-buildmode=c-shared" ]
     args += rebase_path(invoker.sources, build_dir)
   }