Change part class naming scheme

update tests depending on part class naming

compiler/testData/codegen/topLevelMemberInvocation/propertyWithGetter/a1.kt

@@ -0,0 +1,9 @@
+package a
+
+val prop: Int = 0
+    get() {
+        return $prop + 1
+    }
+
+// 2 INVOKESTATIC a/A1Kt.getProp \(\)I
+// 1 GETSTATIC a/A1Kt.prop \: I