Fix lazy type checking of UInt types (#740)

For example, Listing<UInt16> is equivalent to Listing<UInt16>, but not to Listing<UInt32>.

pkl-core/src/main/java/org/pkl/core/ast/type/TypeNode.java

@@ -2153,7 +2153,7 @@ public abstract class TypeNode extends PklNode {
 
     @Override
     public boolean isEquivalentTo(TypeNode other) {
-      return other instanceof UIntTypeAliasTypeNode;
+      return other instanceof UIntTypeAliasTypeNode aliasTypeNode && mask == aliasTypeNode.mask;
     }
 
     @Override

pkl-core/src/test/files/LanguageSnippetTests/input/basic/as2.pkl

@@ -22,6 +22,18 @@ examples {
     new Listing { 1; 2; 3 } as Listing<Int>
     module.catch(() -> (new Listing { 1; 2; 3 } as Listing<String>)[0])
   }
+  
+  ["cast Listing<UInt32> to other integer types"] {
+    local l = new Listing<UInt32> { 9999999 }
+    (l as Listing<Int>)[0]
+    (l as Listing<UInt>)[0]
+    (l as Listing<Int32>)[0]
+    (l as Listing<UInt32>)[0]
+    module.catch(() -> (l as Listing<Int16>)[0])
+    module.catch(() -> (l as Listing<UInt16>)[0])
+    module.catch(() -> (l as Listing<Int8>)[0])
+    module.catch(() -> (l as Listing<UInt8>)[0])
+  }
 
   ["mapping"] {
     module.catch(() -> new Listing { 1; 2; 3 } as Mapping<Int, String>)
@@ -29,6 +41,18 @@ examples {
     module.catch(() -> new Mapping { ["Pigeon"] = 42; ["Barn Owl"] = 21 } as Mapping<Int, String>)
   }
   
+  ["cast Mapping<, UInt> to other integer types"] {
+    local m = new Mapping<String, UInt> { ["x"] = 9999 }
+    (m as Mapping<String, Int>)["x"]
+    (m as Mapping<String, UInt>)["x"]
+    (m as Mapping<String, Int32>)["x"]
+    (m as Mapping<String, UInt32>)["x"]
+    (m as Mapping<String, Int16>)["x"]
+    (m as Mapping<String, UInt16>)["x"]
+    module.catch(() -> (m as Mapping<String, Int8>)["x"])
+    module.catch(() -> (m as Mapping<String, UInt8>)["x"])
+  }
+  
   ["union type"] {
     42 as Int|String
     42 as String|Int

pkl-core/src/test/files/LanguageSnippetTests/output/basic/as2.pcf

@@ -21,6 +21,16 @@ examples {
     }
     "Expected value of type `String`, but got type `Int`. Value: 1"
   }
+  ["cast Listing<UInt32> to other integer types"] {
+    9999999
+    9999999
+    9999999
+    9999999
+    "Type constraint `isBetween(-32768, 32767)` violated. Value: 9999999"
+    "Type constraint `isBetween(0, 65535)` violated. Value: 9999999"
+    "Type constraint `isBetween(-128, 127)` violated. Value: 9999999"
+    "Type constraint `isBetween(0, 255)` violated. Value: 9999999"
+  }
   ["mapping"] {
     "Expected value of type `Mapping`, but got type `Listing`. Value: new Listing { ?; ?; ? }"
     new {
@@ -29,6 +39,16 @@ examples {
     }
     "Expected value of type `Int`, but got type `String`. Value: \"Pigeon\""
   }
+  ["cast Mapping<, UInt> to other integer types"] {
+    9999
+    9999
+    9999
+    9999
+    9999
+    9999
+    "Type constraint `isBetween(-128, 127)` violated. Value: 9999"
+    "Type constraint `isBetween(0, 255)` violated. Value: 9999"
+  }
   ["union type"] {
     42
     42