[FIR TEST] Add CLI test with should-be-error (not yet)

compiler/testData/cli/jvm/firError.args

@@ -0,0 +1,4 @@
+$TESTDATA_DIR$/firError.kt
+-Xuse-fir
+-d
+$TEMP_DIR$

compiler/testData/cli/jvm/firError.kt

@@ -0,0 +1,6 @@
+fun println(val x: Int) {}
+
+fun main() {
+    val x: Int
+    println(x)
+}

compiler/testData/cli/jvm/firError.out

@@ -0,0 +1 @@
+OK