Add -Zcross-crate-inline-threshold=yes

tests/codegen/cross-crate-inlining/never-inline.rs

@@ -0,0 +1,13 @@
+// compile-flags: -O
+// aux-build:never.rs
+
+#![crate_type = "lib"]
+
+extern crate never;
+
+// Check that we do not inline a cross-crate call, even though it is a leaf
+#[no_mangle]
+pub fn outer() -> String {
+    // CHECK: call {{.*}}leaf_fn
+    never::leaf_fn()
+}