ensure cast to class type is suggested when argument type is null (IDEA-159884)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/castMethodParameters15/afterNullType.java

@@ -0,0 +1,9 @@
+// "Cast parameter to 'java.lang.String'" "true"
+class a {
+    void f(Long... l) {}
+    void f(String s) {}
+    void g() {
+        f((String) null);
+    }
+}
+

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/castMethodParameters15/beforeNullType.java

@@ -0,0 +1,9 @@
+// "Cast parameter to 'java.lang.String'" "true"
+class a {
+    void f(Long... l) {}
+    void f(String s) {}
+    void g() {
+        f(<caret>null);
+    }
+}
+