Merge #10977

10977: fix: fix `concat!` with captured expression r=jonas-schievink a=jonas-schievink

Adds another hack on top of https://github.com/rust-analyzer/rust-analyzer/pull/10623 to fix `concat!`.

Fixes https://github.com/rust-analyzer/rust-analyzer/issues/10721

bors r+

Co-authored-by: Jonas Schievink <jonas.schievink@ferrous-systems.com>

crates/hir_def/src/macro_expansion_tests/builtin_fn_macro.rs

@@ -313,6 +313,40 @@ fn main() { "foor0bar\nfalse"; }
     );
 }
 
+#[test]
+fn test_concat_with_captured_expr() {
+    check(
+        r##"
+#[rustc_builtin_macro]
+macro_rules! concat {}
+
+macro_rules! surprise {
+    () => { "s" };
+}
+
+macro_rules! stuff {
+    ($string:expr) => { concat!($string) };
+}
+
+fn main() { concat!(surprise!()); }
+"##,
+        expect![[r##"
+#[rustc_builtin_macro]
+macro_rules! concat {}
+
+macro_rules! surprise {
+    () => { "s" };
+}
+
+macro_rules! stuff {
+    ($string:expr) => { concat!($string) };
+}
+
+fn main() { "s"; }
+"##]],
+    );
+}
+
 #[test]
 fn test_concat_idents_expand() {
     check(