explicit test for java signature writing

(partially replaces CompileJavaAgainstKotlinTest)

compiler/testData/writeSignature/ListOfString.kt

@@ -0,0 +1,9 @@
+import java.util.List
+import java.lang.CharSequence
+
+fun foo(p: List<CharSequence>) = 1
+
+// method: namespace::foo
+// jvm signature:     (Ljava/util/List;)I
+// generic signature: (Ljava/util/List<Ljava/lang/CharSequence;>;)I
+// kotlin signature:  (Ljava/util/List<Ljava/lang/CharSequence;>;)I // TODO: skip Kotlin signature

compiler/testData/writeSignature/NonGeneric.kt

@@ -0,0 +1,6 @@
+fun foo() = 1
+
+// method: namespace::foo
+// jvm signature:     ()I
+// generic signature: ()I // TODO: need to skip generic signature
+// kotlin signature:  ()I // TODO: need to skip kotlin signature