allow delegated properties to have getters and setters without bodies

compiler/testData/diagnostics/tests/delegatedProperty/defaultGetter.kt

@@ -0,0 +1,10 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+val a: Int by Delegate()
+    get
+
+class Delegate {
+    fun get(t: Any?, p: PropertyMetadata): Int {
+        return 1
+    }
+}

compiler/testData/diagnostics/tests/delegatedProperty/defaultGetter.txt

@@ -0,0 +1,11 @@
+package
+
+internal val a: kotlin.Int
+
+internal final class Delegate {
+    public constructor Delegate()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun get(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/testData/diagnostics/tests/delegatedProperty/defaultSetter.kt

@@ -0,0 +1,12 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+var a: Int by Delegate()
+    private set
+
+class Delegate {
+    fun get(t: Any?, p: PropertyMetadata): Int {
+        return 1
+    }
+
+    fun set(t: Any?, p: PropertyMetadata, i: Int) {}
+}

compiler/testData/diagnostics/tests/delegatedProperty/defaultSetter.txt

@@ -0,0 +1,12 @@
+package 
+
+internal var a: kotlin.Int
+
+internal final class Delegate {
+    public constructor Delegate()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal final fun get(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    internal final fun set(/*0*/ t: kotlin.Any?, /*1*/ p: kotlin.PropertyMetadata, /*2*/ i: kotlin.Int): kotlin.Unit
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}