[LL FIR] rename testdata to testData to avoid copyright generation

We exclude testData pattern from copyright scope

analysis/low-level-api-fir/testData/getOrBuildFir/calls/incWithArrayAccessConvention.kt

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+interface A {
+    operator fun inc(): A
+}
+
+interface MyMap<K, V> {
+    operator fun get(k: K): V
+    operator fun set(k: K, v: V): Unit
+}
+
+fun test(m: MyMap<String, A>) {
+    <expr>m["a"]++</expr>
+}