Remove leftovers of platformName and platformStatic in test data

Drop unnecessary imports, rename some tests

compiler/testData/compileJavaAgainstKotlin/jvmStatic/simpleCompanionObjectProperty.kt

@@ -0,0 +1,19 @@
+package test
+
+class A {
+    companion object {
+        @JvmStatic val b: String = "OK"
+
+        var A.c: String
+            @JvmStatic get() = "OK"
+            @JvmStatic set(t: String) {}
+    }
+}
+
+fun main(args: Array<String>) {
+    A.b
+    with(A) {
+        A().c
+        A().c = "123"
+    }
+}