Rust: fix test

Author: redsun82

rust/ql/test/extractor-tests/generated/Function/Function.expected

@@ -1,6 +1,6 @@
 instances
-| gen_function.rs:3:1:4:38 | fn foo | isAsync: | no | isConst: | no | isDefault: | no | isGen: | no | isUnsafe: | no |
-| gen_function.rs:7:5:7:13 | fn bar | isAsync: | no | isConst: | no | isDefault: | no | isGen: | no | isUnsafe: | no |
+| gen_function.rs:3:1:4:38 | fn foo | isAsync: | no | isConst: | no | isDefault: | no | isGen: | no | isUnsafe: | no | hasImplementation: | yes |
+| gen_function.rs:7:5:7:13 | fn bar | isAsync: | no | isConst: | no | isDefault: | no | isGen: | no | isUnsafe: | no | hasImplementation: | no |
 getParamList
 | gen_function.rs:3:1:4:38 | fn foo | gen_function.rs:4:7:4:14 | ParamList |
 | gen_function.rs:7:5:7:13 | fn bar | gen_function.rs:7:11:7:12 | ParamList |