Support some, ok and err wrappers and untyped function inputs

test/fixtures/invalid/anonymous_without_input.ls

@@ -1 +0,0 @@
-identity :: @ value { value }

test/fixtures/invalid/bang_postfix.ls

@@ -0,0 +1 @@
+value :: @ x: i32 -> i32 ! str { x! }

test/fixtures/invalid/bang_prefix.ls

@@ -0,0 +1 @@
+value :: @ x: str -> i32 ! str { !x }

test/fixtures/invalid/keyword_ok_identifier.ls

@@ -0,0 +1 @@
+ok :: @ value { value }

test/fixtures/invalid/keyword_some_identifier.ls

@@ -0,0 +1 @@
+some := 1

test/fixtures/invalid/legacy_some_constructor.ls

@@ -0,0 +1 @@
+value: i32?: 1->|.some

test/fixtures/invalid/legacy_some_pattern.ls

@@ -0,0 +1 @@
+value :: @ x: i32? { match x { |.some y => y; nil => 0 } }