Parsing: allow semicolon between declarations

compiler/testData/psi/semicolonBetweenDeclarations.kt

@@ -0,0 +1,27 @@
+package foo;
+
+fun foo1() {};
+val x = 1;;;;
+class A() {
+    val x = 1;
+
+    fun foo() {
+        class A1;
+        val x = 1;
+    }
+    fun bar();
+
+    init {};
+
+    constructor() : super();
+
+    companion object {};
+};
+
+fun foo;
+val;
+class B {
+    val;
+    init;
+    constructor;
+}