enable tt feature in crates/cfg tests

Author: Elliot-Roberts

src/tools/rust-analyzer/Cargo.lock

@@ -235,6 +235,7 @@ name = "cfg"
 version = "0.0.0"
 dependencies = [
  "arbitrary",
+ "cfg",
  "expect-test",
  "intern",
  "oorandom",

src/tools/rust-analyzer/crates/cfg/Cargo.toml

@@ -29,5 +29,8 @@ arbitrary = { version = "1.4.1", features = ["derive"] }
 syntax-bridge.workspace = true
 syntax.workspace = true
 
+# tt is needed for testing
+cfg = { path = ".", default-features = false, features = ["tt"] }
+
 [lints]
 workspace = true