equals should not be used on withTimeout results

Fixes #212.

Author: konrad-kaminski

common/kotlinx-coroutines-core-common/src/main/kotlin/kotlinx/coroutines/experimental/intrinsics/Undispatched.kt

@@ -83,7 +83,7 @@ private inline fun <T> AbstractCoroutine<T>.undispatchedResult(startBlock: () ->
         CompletedExceptionally(e)
     }
     return when {
-        result == COROUTINE_SUSPENDED -> COROUTINE_SUSPENDED
+        result === COROUTINE_SUSPENDED -> COROUTINE_SUSPENDED
         makeCompletingOnce(result, MODE_IGNORE) -> {
             if (result is CompletedExceptionally) throw result.exception else result
         }

common/kotlinx-coroutines-core-common/src/test/kotlin/kotlinx/coroutines/experimental/CommonWithTimeoutTest.kt

@@ -109,5 +109,20 @@ class CommonWithTimeoutTest : TestBase() {
         }
         finish(5)
     }
+
+    @Test
+    fun testBadClass() = runTest {
+        val bad = BadClass()
+        val result = withTimeout(100) {
+            bad
+        }
+        assertSame(bad, result)
+    }
+
+    class BadClass {
+        override fun equals(other: Any?): Boolean = error("Should not be called")
+        override fun hashCode(): Int = error("Should not be called")
+        override fun toString(): String = error("Should not be called")
+    }
 }