Fix name resolution of types in constraints (#1826)

This fixes an issue where type names are resolved incorrectly
in typealias constraints.

Co-authored-by: Islon Scherer <islonscherer@gmail.com>

pkl-core/src/test/files/LanguageSnippetTests/input-helper/types/typeAliasConstraint2.pkl

@@ -1,3 +1,8 @@
 class MyClass
 
 typealias MyTypeAlias = MyClass(getClass() == MyClass)
+
+typealias MyTypeAlias2 = MyClass(this is MyClass)
+
+// a let expression turns the constraint node into its own root node
+typealias MyTypeAlias3 = MyClass(let (_ = true) this is MyClass)

pkl-core/src/test/files/LanguageSnippetTests/input-helper/types/typeAliasConstraint3.pkl

@@ -0,0 +1,3 @@
+import "typeAliasConstraint2.pkl"
+
+typealias MyTypeAlias = Any(this is typeAliasConstraint2.MyClass)

pkl-core/src/test/files/LanguageSnippetTests/input/types/typeAliasConstraint10.pkl

@@ -0,0 +1,8 @@
+import "../../input-helper/types/typeAliasConstraint2.pkl"
+import "../../input-helper/types/typeAliasConstraint3.pkl"
+
+res: typeAliasConstraint2.MyTypeAlias2 = new typeAliasConstraint2.MyClass {}
+
+res2: typeAliasConstraint3.MyTypeAlias = new typeAliasConstraint2.MyClass {}
+
+res3: typeAliasConstraint2.MyTypeAlias3 = new typeAliasConstraint2.MyClass {}

pkl-core/src/test/files/LanguageSnippetTests/input/types/typeAliasConstraint9.pkl

@@ -0,0 +1,6 @@
+import "../../input-helper/types/typeAliasAmendModule.pkl"
+
+local const function isValid(s: String): Boolean = s.startsWith("Alice")
+
+res = typeAliasAmendModule.name
+

pkl-core/src/test/files/LanguageSnippetTests/output/types/typeAliasConstraint10.pcf

@@ -0,0 +1,3 @@
+res {}
+res2 {}
+res3 {}

pkl-core/src/test/files/LanguageSnippetTests/output/types/typeAliasConstraint9.pcf

@@ -0,0 +1 @@
+res = "Bob Marley"