[IR] Fix the type of the default argument mask condition.

On JVM and JS we can get away with using an Int but it really
should be a Boolean and Native reasonably insists on that.

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/DefaultArgumentStubGenerator.kt

@@ -193,7 +193,7 @@ open class DefaultArgumentStubGenerator(
         //
         // This control flow limits us to an if-then (without an else), and this together with the
         // restriction on loading the parameter in the default case means we cannot create any temporaries.
-        +irIfThen(defaultFlag, irSet(parameter.symbol, default))
+        +irIfThen(irNotEquals(defaultFlag, irInt(0)), irSet(parameter.symbol, default))
         return parameter
     }