Add basic lowering and WF tests for FnDefs

Author: nathanwhit

tests/lowering/mod.rs

@@ -559,3 +559,28 @@ fn slices() {
         }
     }
 }
+
+#[test]
+fn fn_defs() {
+    lowering_success! {
+        program {
+            trait Quux { }
+
+            fn foo<'a, T>(bar: T, baz: &'a mut T) -> u32
+                where T: Quux;
+        }
+    }
+
+    lowering_error! {
+        program {
+            trait Quux { }
+
+            fn foo<T>(bar: TT) -> T
+                where T: Quux;
+        }
+
+        error_msg {
+            "invalid type name `TT`"
+        }
+    }
+}

tests/test/functions.rs

@@ -23,3 +23,42 @@ fn functions_are_sized() {
         }
     }
 }
+
+#[test]
+fn fn_defs() {
+    test! {
+        program {
+            trait Foo { }
+
+            struct Bar { }
+
+            struct Xyzzy { }
+            impl Foo for Xyzzy { }
+
+            fn baz<T>(quux: T) -> T
+                where T: Foo;
+
+            fn garply(thud: i32) -> i32;
+        }
+
+        goal {
+            WellFormed(baz<Bar>)
+        } yields {
+            "No possible solution"
+        }
+
+        goal {
+            WellFormed(baz<Xyzzy>)
+        } yields {
+            "Unique"
+        }
+
+        goal {
+            WellFormed(garply)
+        } yields {
+            "Unique"
+        }
+
+
+    }
+}