Refactor CompileKotlinAgainstKotlinTest

CKAKTest is now abstract, the actual testcases are generated via GenerateTests
into CompileKotlinAgainstKotlinTestGenerated.

Also invokeMain() now invokes namespace.main instead of bbb.namespace.main.

compiler/testData/compileKotlinAgainstKotlin/Simple.B.kt

@@ -0,0 +1,6 @@
+fun main(args: Array<String>) {
+    val h = aaa.hello()
+    if (h != 17) {
+        throw Exception()
+    }
+}