ty: normalize fn sigs before subst

This commit normalizes function signatures for instances before
substituting, a workaround for polymorphization considering
parameters unused when they show up in the signature, but not the
body (due to being normalized).

Unfortunately, this causes test output to change with the parallel
compiler only.

Signed-off-by: David Wood <david@davidtw.co>

1 files changed, 25 insertions, 0 deletions

diff --git a/src/test/ui/polymorphization/normalized_sig_types.rs b/src/test/ui/polymorphization/normalized_sig_types.rs
new file mode 100644
index 00000000000..fa76b7201e8
--- /dev/null
+++ b/src/test/ui/polymorphization/normalized_sig_types.rs
@@ -0,0 +1,25 @@
+// build-pass
+
+pub trait ParallelIterator: Sized {
+    fn drive<C: Consumer<()>>(_: C) {
+        C::into_folder();
+    }
+}
+
+pub trait Consumer<T>: Sized {
+    type Result;
+    fn into_folder() -> Self::Result;
+}
+
+impl ParallelIterator for () {}
+
+impl<F: Fn(), T> Consumer<T> for F {
+    type Result = ();
+    fn into_folder() -> Self::Result {
+        unimplemented!()
+    }
+}
+
+fn main() {
+    <()>::drive(|| ());
+}