Type inference ignores generic arguments (#1551)

This PR solves issue #1550

importer/src/path_canonicalizer.rs

@@ -253,7 +253,7 @@ fn canonicalize_inside_expression(
             Expression::Reference(_, reference) => {
                 // If resolving the reference fails, we assume it is a local variable that has been checked below.
                 if let Some(n) = paths.get(&path.clone().join(reference.path.clone())) {
-                    *reference = n.relative_to(&Default::default()).into();
+                    reference.path = n.relative_to(&Default::default());
                 } else {
                     assert!(reference.path.try_to_identifier().is_some());
                 }

pipeline/tests/asm.rs

@@ -731,3 +731,9 @@ fn connect_no_witgen() {
     let i = [];
     verify_asm(f, slice_to_vec(&i));
 }
+
+#[test]
+fn generics_preservation() {
+    let f = "asm/generics_preservation.asm";
+    verify_asm(f, Default::default());
+}

test_data/asm/generics_preservation.asm

@@ -0,0 +1,20 @@
+mod cols {
+    enum Generic<T> {
+        A(T),
+        B,
+    }
+    let<T> f: -> Generic<T> = || {
+            Generic::B
+    };
+}
+
+
+machine Empty {
+    let x;
+    let fi: col = |i| match cols::f::<int>() {
+        cols::Generic::A(_) => 7,
+        cols::Generic::B => 9,
+    };
+    x = fi;
+
+}