Rename test data folder: libraries -> decompiler

idea/testData/decompiler/decompiledText/TestPackage.expected.kt

@@ -0,0 +1,13 @@
+// IntelliJ API Decompiler stub source generated from a class file
+// Implementation of methods is not available
+
+package test
+
+private var i: kotlin.Int /* compiled code */
+
+internal val p: kotlin.Int /* compiled code */
+
+internal fun f(): kotlin.Unit { /* compiled code */ }
+
+internal fun kotlin.Int.plus(i: kotlin.Int): kotlin.Int { /* compiled code */ }
+