Mark only unreachable parts of element if it has reachable parts

like for 'return todo()' mark only 'return'

compiler/testData/diagnostics/tests/controlFlowAnalysis/deadCode/deadCodeInLocalDeclarations.kt

@@ -0,0 +1,36 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+fun testObject() {
+    <!UNREACHABLE_CODE!>object : Foo(<!>todo()<!UNREACHABLE_CODE!>) {
+        fun foo() = 1
+    }<!>
+}
+
+fun testObjectExpression() {
+    <!UNREACHABLE_CODE!>val <!UNUSED_VARIABLE!>a<!>  = object : Foo(<!>todo()<!UNREACHABLE_CODE!>) {
+        fun foo() = 1
+    }<!>
+}
+
+fun testObjectExpression1() {
+    fun bar(i: Int, x: Any) {}
+
+    <!UNREACHABLE_CODE!>bar(<!>1, <!UNREACHABLE_CODE!>object : Foo(<!>todo()<!UNREACHABLE_CODE!>) {
+        fun foo() = 1
+    })<!>
+}
+
+fun testClassDeclaration() {
+    class C : Foo(todo()) {}
+
+    <!UNREACHABLE_CODE!>bar()<!>
+}
+
+fun testFunctionDefaultArgument() {
+    fun foo(x: Int = todo()) { bar() }
+}
+
+open class Foo(i: Int) {}
+
+fun todo() = throw Exception()
+fun bar() {}