Mark only unreachable parts of element if it has reachable parts

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

compiler/testData/diagnostics/tests/controlFlowAnalysis/deadCode/kt2585_2.kt

@@ -0,0 +1,23 @@
+//KT-2585 Code in try-finally is incorrectly marked as unreachable
+
+fun foo() {
+    try {
+        <!UNREACHABLE_CODE!>throw<!> RuntimeException()
+    } catch (e: Exception) {
+        <!UNREACHABLE_CODE!>return<!>     // <- Wrong UNREACHABLE_CODE
+    } finally {
+        while (true);
+    }
+}
+
+fun bar() {
+    try {
+        throw RuntimeException()
+    } catch (e: Exception) {
+        return     // <- Wrong UNREACHABLE_CODE
+    } finally {
+        while (cond());
+    }
+}
+
+fun cond() = true