[FIR] KT-54220: Don't crash on unsigned integers when no stdlib present

^KT-54220 Fixed

compiler/fir/analysis-tests/testData/resolve/kt54220.fir.txt

@@ -0,0 +1,14 @@
+FILE: kt54220.kt
+    public final const val c: R|kotlin/String| = ERROR_EXPR(Unsigned integers need stdlib).R|kotlin/plus|(ERROR_EXPR(Unsigned integers need stdlib))
+        public get(): R|kotlin/String|
+    public final fun box(): R|kotlin/String| {
+        ^box when () {
+            !=(R|/c|, ERROR_EXPR(Unsigned integers need stdlib)) ->  {
+                String(fail)
+            }
+            else ->  {
+                String(OK)
+            }
+        }
+
+    }

compiler/fir/analysis-tests/testData/resolve/kt54220.kt

@@ -0,0 +1,6 @@
+const val c = <!CONST_VAL_WITH_NON_CONST_INITIALIZER!><!UNSIGNED_LITERAL_WITHOUT_DECLARATIONS_ON_CLASSPATH!>1u<!> + <!UNSIGNED_LITERAL_WITHOUT_DECLARATIONS_ON_CLASSPATH!>2u<!><!>
+
+fun box() = when {
+    c != <!UNSIGNED_LITERAL_WITHOUT_DECLARATIONS_ON_CLASSPATH!>3u<!> -> "fail"
+    else -> "OK"
+}