Fix unifying pure with flex vars

crates/compiler/load/tests/helpers/mod.rs

@@ -204,7 +204,7 @@ pub fn can_expr_with<'a>(
             rigids: MutMap::default(),
             home,
             resolutions_to_make: vec![],
-            enclosing_fx: None,
+            fx_expectation: None,
         },
         loc_expr.region,
         &loc_expr.value,

crates/compiler/load/tests/test_reporting.rs

@@ -5419,9 +5419,9 @@ mod test_reporting {
     6│       2 -> 2
                ^^
 
-    Looks like you are trying to define a function.
+    Looks like you are trying to define a function. 
 
-    In Roc, functions are always written as a lambda, like
+    In Roc, functions are always written as a lambda, like 
 
         increment = \n -> n + 1
     "#
@@ -14762,6 +14762,16 @@ All branches in an `if` must have the same type!
 
     You can still run the program with this error, which can be helpful
     when you're debugging.
+
+    ── UNNECESSARY EXCLAMATION in /code/proj/Main.roc ──────────────────────────────
+
+    This function is pure, but its name suggests otherwise:
+
+    5│  main! = \{} ->
+        ^^^^^
+
+    Remove the exclamation mark to give an accurate impression of its
+    behavior.
     "###
     );