Merge #4234

4234: Support local_inner_macros r=jonas-schievink a=edwin0cheng

This PR implements `#[macro_export(local_inner_macros)]` support. 

Note that the rustc implementation is quite [hacky][1] too. :)

[1]: 614f273e93/src/librustc_resolve/macros.rs (L456)

Co-authored-by: Edwin Cheng <edwin0cheng@gmail.com>

crates/ra_hir_ty/src/tests/macros.rs

@@ -427,6 +427,32 @@ fn main() {
     );
 }
 
+#[test]
+fn infer_local_inner_macros() {
+    let (db, pos) = TestDB::with_position(
+        r#"
+//- /main.rs crate:main deps:foo
+fn test() {
+    let x = foo::foo!(1);
+    x<|>;
+}
+
+//- /lib.rs crate:foo
+#[macro_export(local_inner_macros)]
+macro_rules! foo {
+    (1) => { bar!() };
+}
+
+#[macro_export]
+macro_rules! bar {
+    () => { 42 }
+}
+
+"#,
+    );
+    assert_eq!("i32", type_at_pos(&db, pos));
+}
+
 #[test]
 fn infer_builtin_macros_line() {
     assert_snapshot!(