Debugger: Fix completion for synthetic '_field' extension properties (KT-23586)

idea/idea-jvm/src/org/jetbrains/kotlin/idea/debugger/evaluate/DebuggerFieldKotlinIndicesHelperExtension.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.debugger.evaluate
+
+import org.jetbrains.kotlin.descriptors.CallableDescriptor
+import org.jetbrains.kotlin.descriptors.ModuleDescriptor
+import org.jetbrains.kotlin.idea.core.extension.KotlinIndicesHelperExtension
+import org.jetbrains.kotlin.incremental.components.LookupLocation
+import org.jetbrains.kotlin.incremental.components.LookupTracker
+import org.jetbrains.kotlin.storage.LockBasedStorageManager
+import org.jetbrains.kotlin.synthetic.JavaSyntheticPropertiesScope
+import org.jetbrains.kotlin.types.KotlinType
+
+class DebuggerFieldKotlinIndicesHelperExtension : KotlinIndicesHelperExtension {
+    override fun appendExtensionCallables(
+        consumer: MutableList<in CallableDescriptor>,
+        moduleDescriptor: ModuleDescriptor,
+        receiverTypes: Collection<KotlinType>,
+        nameFilter: (String) -> Boolean,
+        lookupLocation: LookupLocation
+    ) {
+        val javaPropertiesScope = JavaSyntheticPropertiesScope(LockBasedStorageManager.NO_LOCKS, LookupTracker.DO_NOTHING)
+        val fieldScope = DebuggerFieldSyntheticScope(javaPropertiesScope)
+
+        for (property in fieldScope.getSyntheticExtensionProperties(receiverTypes, lookupLocation)) {
+            if (nameFilter(property.name.asString())) {
+                consumer += property
+            }
+        }
+    }
+}

idea/idea-jvm/src/org/jetbrains/kotlin/idea/debugger/evaluate/DebuggerFieldSyntheticScopeProvider.kt

@@ -46,7 +46,7 @@ class DebuggerFieldSyntheticScopeProvider : SyntheticScopeProviderExtension {
     }
 }
 
-private class DebuggerFieldSyntheticScope(val javaSyntheticPropertiesScope: JavaSyntheticPropertiesScope) : SyntheticScope.Default() {
+class DebuggerFieldSyntheticScope(val javaSyntheticPropertiesScope: JavaSyntheticPropertiesScope) : SyntheticScope.Default() {
     private val javaSourceElementFactory = JavaSourceElementFactoryImpl()
 
     override fun getSyntheticExtensionProperties(