[FIR] Introduce extended checkers for inspection-like diagnostics

compiler/fir/analysis-tests/testData/extendedCheckers/RedundantVisibilityModifierChecker.kt

@@ -0,0 +1,52 @@
+<!REDUNDANT_VISIBILITY_MODIFIER!>public<!> class C {
+    <!REDUNDANT_VISIBILITY_MODIFIER!>public<!> val foo: Int = 0
+
+    <!REDUNDANT_VISIBILITY_MODIFIER!>public<!> fun bar() {}
+
+}
+
+open class D {
+    protected open fun willRemainProtected() {
+    }
+
+    protected open fun willBecomePublic() {
+    }
+}
+
+class E : D() {
+    <!REDUNDANT_VISIBILITY_MODIFIER!>protected<!> override fun willRemainProtected() {
+    }
+
+    public override fun willBecomePublic() {
+    }
+}
+
+enum class F <!REDUNDANT_VISIBILITY_MODIFIER!>private<!> constructor(val x: Int) {
+    FIRST(42)
+}
+
+sealed class G constructor(val y: Int) {
+    <!REDUNDANT_VISIBILITY_MODIFIER!>private<!> constructor(): this(42)
+
+    object H : G()
+}
+
+interface I {
+    fun bar()
+}
+
+fun f() {
+    val i = object : I {
+        <!REDUNDANT_VISIBILITY_MODIFIER!>internal<!> var foo = 0
+        override fun bar() {}
+    }
+    i.foo = 1
+
+    class LocalClass {
+        <!REDUNDANT_VISIBILITY_MODIFIER!>internal<!> var foo = 0
+    }
+    LocalClass().foo = 1
+    <!REDUNDANT_VISIBILITY_MODIFIER!>public<!> var baz = 0
+}
+
+<!REDUNDANT_VISIBILITY_MODIFIER!>public<!> var baz = 0