Extend UI tests for fixed check_attr()

Add testcases for the `#[track_caller]` and `#[target_feature(..)]`
function attributes for errors that were not not caught before.

Author: neocturne

src/test/ui/rfc-2091-track-caller/error-with-invalid-abi.rs

@@ -4,4 +4,10 @@
 extern "C" fn f() {}
 //~^^ ERROR `#[track_caller]` requires Rust ABI
 
+extern "C" {
+    #[track_caller]
+    fn g();
+    //~^^ ERROR `#[track_caller]` requires Rust ABI
+}
+
 fn main() {}

src/test/ui/rfc-2091-track-caller/error-with-invalid-abi.stderr

@@ -4,6 +4,12 @@ error[E0737]: `#[track_caller]` requires Rust ABI
 LL | #[track_caller]
    | ^^^^^^^^^^^^^^^
 
-error: aborting due to previous error
+error[E0737]: `#[track_caller]` requires Rust ABI
+  --> $DIR/error-with-invalid-abi.rs:8:5
+   |
+LL |     #[track_caller]
+   |     ^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0737`.

src/test/ui/target-feature/invalid-attribute.rs

@@ -65,9 +65,26 @@ trait Baz { }
 #[target_feature(enable = "sse2")]
 unsafe fn test() {}
 
+trait Quux {
+    fn foo();
+}
+
+impl Quux for Foo {
+    #[target_feature(enable = "sse2")]
+    //~^ ERROR `#[target_feature(..)]` can only be applied to `unsafe` functions
+    //~| NOTE can only be applied to `unsafe` functions
+    fn foo() {}
+    //~^ NOTE not an `unsafe` function
+}
+
 fn main() {
     unsafe {
         foo();
         bar();
     }
+    #[target_feature(enable = "sse2")]
+    //~^ ERROR `#[target_feature(..)]` can only be applied to `unsafe` functions
+    //~| NOTE can only be applied to `unsafe` functions
+    || {};
+    //~^ NOTE not an `unsafe` function
 }

src/test/ui/target-feature/invalid-attribute.stderr

@@ -91,5 +91,23 @@ error: cannot use `#[inline(always)]` with `#[target_feature]`
 LL | #[inline(always)]
    | ^^^^^^^^^^^^^^^^^
 
-error: aborting due to 12 previous errors
+error: `#[target_feature(..)]` can only be applied to `unsafe` functions
+  --> $DIR/invalid-attribute.rs:85:5
+   |
+LL |     #[target_feature(enable = "sse2")]
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can only be applied to `unsafe` functions
+...
+LL |     || {};
+   |     ----- not an `unsafe` function
+
+error: `#[target_feature(..)]` can only be applied to `unsafe` functions
+  --> $DIR/invalid-attribute.rs:73:5
+   |
+LL |     #[target_feature(enable = "sse2")]
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ can only be applied to `unsafe` functions
+...
+LL |     fn foo() {}
+   |     ----------- not an `unsafe` function
+
+error: aborting due to 14 previous errors