JetCompilerMessagingTest and K2JSCompilerMessagingTest: tests that launch the cli compiler and check that resulting messages are in correct format

idea/testData/compilerMessages/k2jvm/helloWorld/src/test.kt

@@ -0,0 +1,3 @@
+package foo
+
+fun main(args : Array<String>) {}

idea/testData/compilerMessages/k2jvm/simpleError/src/test.kt

@@ -0,0 +1,5 @@
+package foo
+
+fun f() : Boolean {
+
+}

idea/testData/compilerMessages/k2jvm/simpleWarning/src/test.kt

@@ -0,0 +1,5 @@
+package foo
+
+fun f(s : String) {
+  s!!
+}