Fix toRadixString on math.minInt (#1656)

Closes #1655

pkl-core/src/main/java/org/pkl/core/stdlib/base/IntNodes.java

@@ -1,5 +1,5 @@
 /*
- * Copyright © 2024 Apple Inc. and the Pkl project authors. All rights reserved.
+ * Copyright © 2024-2026 Apple Inc. and the Pkl project authors. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -190,7 +190,7 @@ public final class IntNodes {
     @Specialization
     @TruffleBoundary
     protected String eval(long self, long radix) {
-      return (self < 0 ? "-" : "") + Long.toString(Math.abs(self), (int) radix);
+      return Long.toString(self, (int) radix);
     }
   }
 

pkl-core/src/test/files/LanguageSnippetTests/input/api/int.pkl

@@ -1,5 +1,7 @@
 amends "../snippetTest.pkl"
 
+import "pkl:math"
+
 facts {
   ["isEven"] {
     (-124).isEven
@@ -110,6 +112,8 @@ examples {
     (-0).toRadixString(2)
     (-0).toRadixString(33)
 
+    math.minInt.toRadixString(10)
+
     module.catch(() -> (-123).toRadixString(-1))
     module.catch(() -> (-123).toRadixString(64))
   }

pkl-core/src/test/files/LanguageSnippetTests/output/api/int.pcf

@@ -90,6 +90,7 @@ examples {
     "0"
     "0"
     "0"
+    "-9223372036854775808"
     "Type constraint `this.isBetween(2, 36)` violated. Value: -1"
     "Type constraint `this.isBetween(2, 36)` violated. Value: 64"
   }