Fix for KT-19188

Fixes nondeterministic Default Method Order under existance of generic
type parameters.
SubstitutingScope did not respect source code method order by not using
a LinkedHashSet

compiler/tests/org/jetbrains/kotlin/codegen/MethodOrderTest.kt

@@ -107,6 +107,31 @@ class MethodOrderTest: CodegenTestCase() {
         )
     }
 
+    fun testDeterministicDefaultMethodImplOrder() {
+        doTest(
+                """
+                    interface Base<K, V> {
+                        fun getSize(): Int = 5
+                        fun size(): Int = getSize()
+                        fun getKeys(): Int = 4
+                        fun keySet() = getKeys()
+                        fun getEntries(): Int = 3
+                        fun entrySet() = getEntries()
+                        fun getValues(): Int = 2
+                        fun values() = getValues()
+
+                        fun removeEldestEntry(eldest: Any?): Boolean
+                    }
+
+                    class MinMap<K, V> : Base<K, V> {
+                        override fun removeEldestEntry(eldest: Any?) = true
+                    }
+                """,
+                "MinMap",
+                listOf("removeEldestEntry(Ljava/lang/Object;)Z", "<init>()V", "getSize()I", "size()I", "getKeys()I", "keySet()I", "getEntries()I", "entrySet()I", "getValues()I", "values()I")
+        )
+    }
+
     private fun doTest(sourceText: String, classSuffix: String, expectedOrder: List<String>) {
         createEnvironmentWithMockJdkAndIdeaAnnotations(ConfigurationKind.JDK_ONLY)
         myFiles = CodegenTestFiles.create("file.kt", sourceText, myEnvironment!!.project)

core/descriptors/src/org/jetbrains/kotlin/resolve/scopes/SubstitutingScope.kt

@@ -23,7 +23,7 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.resolve.calls.inference.wrapWithCapturingSubstitution
 import org.jetbrains.kotlin.types.TypeSubstitutor
 import org.jetbrains.kotlin.utils.Printer
-import org.jetbrains.kotlin.utils.newHashSetWithExpectedSize
+import org.jetbrains.kotlin.utils.newLinkedHashSetWithExpectedSize
 import org.jetbrains.kotlin.utils.sure
 import java.util.*
 
@@ -60,7 +60,7 @@ class SubstitutingScope(private val workerScope: MemberScope, givenSubstitutor:
         if (substitutor.isEmpty) return descriptors
         if (descriptors.isEmpty()) return descriptors
 
-        val result = newHashSetWithExpectedSize<D>(descriptors.size)
+        val result = newLinkedHashSetWithExpectedSize<D>(descriptors.size)
         for (descriptor in descriptors) {
             val substitute = substitute(descriptor)
             result.add(substitute)