JS: minor, simplify code locating default argument values

At the only call site of getDefaultArgument it is checked that the
parameter actually _declares_ default value, so it's not necessary to
try to load that value from supertypes

js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/BindingUtils.java

@@ -30,7 +30,6 @@ import org.jetbrains.kotlin.resolve.calls.callUtil.CallUtilKt;
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall;
 import org.jetbrains.kotlin.resolve.constants.CompileTimeConstant;
 import org.jetbrains.kotlin.resolve.constants.evaluate.ConstantExpressionEvaluator;
-import org.jetbrains.kotlin.resolve.descriptorUtil.DescriptorUtilsKt;
 import org.jetbrains.kotlin.types.KotlinType;
 import org.jetbrains.kotlin.types.TypeUtils;
 
@@ -178,26 +177,12 @@ public final class BindingUtils {
 
     @NotNull
     public static KtExpression getDefaultArgument(@NotNull ValueParameterDescriptor parameterDescriptor) {
-        ValueParameterDescriptor descriptorWhichDeclaresDefaultValue =
+        KtParameter psiParameter = getParameterForDescriptor(parameterDescriptor);
-                getOriginalDescriptorWhichDeclaresDefaultValue(parameterDescriptor);
-        KtParameter psiParameter = getParameterForDescriptor(descriptorWhichDeclaresDefaultValue);
         KtExpression defaultValue = psiParameter.getDefaultValue();
         assert defaultValue != null : message(parameterDescriptor, "No default value found in PSI");
         return defaultValue;
     }
 
-    private static ValueParameterDescriptor getOriginalDescriptorWhichDeclaresDefaultValue(
-            @NotNull ValueParameterDescriptor parameterDescriptor
-    ) {
-        ValueParameterDescriptor result = parameterDescriptor;
-        assert DescriptorUtilsKt.hasDefaultValue(result) : message(parameterDescriptor, "Unsupplied parameter must have default value");
-        // TODO: this seems incorrect, as the default value may come from _not the first_ overridden parameter
-        while (!result.declaresDefaultValue()) {
-            result = result.getOverriddenDescriptors().iterator().next();
-        }
-        return result;
-    }
-
     @NotNull
     public static ResolvedCall<FunctionDescriptor> getIteratorFunction(@NotNull BindingContext context,
             @NotNull KtExpression rangeExpression) {

js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/FunctionBodyTranslator.java

@@ -43,7 +43,6 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
-import static org.jetbrains.kotlin.js.translate.utils.BindingUtils.getDefaultArgument;
 import static org.jetbrains.kotlin.js.translate.utils.JsAstUtils.*;
 import static org.jetbrains.kotlin.js.translate.utils.mutator.LastExpressionMutator.mutateLastExpression;
 
@@ -84,7 +83,7 @@ public final class FunctionBodyTranslator extends AbstractTranslator {
             if (!valueParameter.declaresDefaultValue()) continue;
 
             JsExpression jsNameRef = ReferenceTranslator.translateAsValueReference(valueParameter, functionBodyContext);
-            KtExpression defaultArgument = getDefaultArgument(valueParameter);
+            KtExpression defaultArgument = BindingUtils.getDefaultArgument(valueParameter);
             JsBlock defaultArgBlock = new JsBlock();
             JsExpression defaultValue = Translation.translateAsExpression(defaultArgument, functionBodyContext, defaultArgBlock);
             PsiElement psi = KotlinSourceElementKt.getPsi(valueParameter.getSource());