Java: Avoid duplicates for shadowed members in completion list for arguments of reflection calls. Simplify building the list of method names with PsiClass.getVisibleSignatures() (IDEA-167250)

java/java-tests/testData/codeInsight/completion/reflectionOverload/OverloadedMethod_after.java

@@ -0,0 +1,10 @@
+class Main {
+  void foo() {
+    Test.class.getMethod("overloaded", int.class);
+  }
+}
+
+class Test {
+  public void overloaded(){}
+  public void overloaded(int n){}
+}