Get rid of CompileKotlinAgainstMultifileKotlinTestGenerated and boxMultifileClasses/

Merge tests in boxMultifileClasses/calls to one test case; copy the two
resulting tests (+ change box to main) to compileKotlinAgainstKotlin

compiler/testData/compileKotlinAgainstKotlin/callsToMultifileClassFromOtherPackage.kt

@@ -0,0 +1,21 @@
+// FILE: A.kt
+
+@file:[JvmName("MultifileClass") JvmMultifileClass]
+package a
+
+fun foo(): String = "OK"
+const val constOK: String = "OK"
+val valOK: String = "OK"
+var varOK: String = "Hmmm?"
+
+// FILE: B.kt
+
+import a.*
+
+fun main(args: Array<String>) {
+    if (foo() != "OK") throw AssertionError("Fail function")
+    if (constOK != "OK") throw AssertionError("Fail const")
+    if (valOK != "OK") throw AssertionError("Fail val")
+    varOK = "OK"
+    if (varOK != "OK") throw AssertionError("Fail var")
+}