Fix "Cannot resolve method" error in Java for methods from trait

compiler/jet.as.java.psi/src/org/jetbrains/jet/asJava/KotlinLightMethodForDeclaration.kt

@@ -112,7 +112,10 @@ public class KotlinLightMethodForDeclaration(
     override fun getUseScope(): SearchScope = origin.getUseScope()
 
     override fun equals(other: Any?): Boolean =
-            other is KotlinLightMethodForDeclaration && getName() == other.getName() && origin == other.origin
+            other is KotlinLightMethodForDeclaration &&
+            getName() == other.getName() &&
+            origin == other.origin &&
+            getContainingClass() == other.getContainingClass()
 
-    override fun hashCode(): Int = getName().hashCode() * 31 + origin.hashCode()
+    override fun hashCode(): Int = (getName().hashCode() * 31 + origin.hashCode()) * 31 + getContainingClass()!!.hashCode()
 }

idea/testData/kotlinAndJavaChecker/ImplementedMethodsFromTraits.java

@@ -0,0 +1,6 @@
+class C {
+    public C(B b, A a) {
+        a.foo();
+        b.foo();
+    }
+}

idea/testData/kotlinAndJavaChecker/ImplementedMethodsFromTraits.kt

@@ -0,0 +1,6 @@
+public trait A {
+    public fun foo() {}
+}
+
+public class B: A {
+}

idea/tests/org/jetbrains/jet/checkers/KotlinAndJavaCheckerTest.java

@@ -69,4 +69,8 @@ public class KotlinAndJavaCheckerTest extends KotlinDaemonAnalyzerTestCase {
     public void testUseKotlinSubclassesOfMappedTypes() throws Exception {
         doTest(true, true, "UseKotlinSubclassesOfMappedTypes.java", "UseKotlinSubclassesOfMappedTypes.kt");
     }
+
+    public void testImplementedMethodsFromTraits() throws Exception {
+        doTest(true, true, "ImplementedMethodsFromTraits.java", "ImplementedMethodsFromTraits.kt");
+    }
 }