correctly calculate the number of mask arguments required for a method with default arguments

#KT-6816 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/state/JetTypeMapper.java

@@ -708,7 +708,7 @@ public class JetTypeMapper {
     @NotNull
     public static String getDefaultDescriptor(@NotNull Method method, boolean isExtension) {
         String descriptor = method.getDescriptor();
-        int argumentsCount = (Type.getArgumentsAndReturnSizes(descriptor) >> 2) - 1;
+        int argumentsCount = Type.getArgumentTypes(descriptor).length;
         if (isExtension) {
             argumentsCount--;
         }

compiler/testData/codegen/box/classes/kt6816.kt

@@ -0,0 +1,25 @@
+public class CalculatorConstants(
+        val id: Long = 0,
+        val detour: Double = 0.0,
+        val taxi: Double = 0.0,
+        val loop: Double = 0.0,
+        val planeCondition: Double = 0.0,
+        val co2PerKerosene: Double = 0.0,
+        val freight: Double = 0.0,
+        val rfi: Double = 0.0,
+        val rfiAltitude: Double = 0.0,
+        val averageContribution: Double = 0.0,
+        val singleContribution: Double = 0.0,
+        val returnContribution: Double = 0.0,
+        val defraFactor: Double = 0.0,
+        val airCondMult: Double = 0.0,
+        val autoTransMult: Double = 0.0,
+        val hybridDefault: String? = null,
+        val travelClassOne: Double = 0.0,
+        val status: String = "OK"
+)
+
+fun box(): String {
+    val c = CalculatorConstants()
+    return c.status
+}

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java

@@ -1451,6 +1451,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             doTest(fileName);
         }
 
+        @TestMetadata("kt6816.kt")
+        public void testKt6816() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/classes/kt6816.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("kt707.kt")
         public void testKt707() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/classes/kt707.kt");