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_3.kt

@@ -0,0 +1,9 @@
+//KT-2585 Code in try-finally is incorrectly marked as unreachable
+
+fun foo(<!UNUSED_PARAMETER!>x<!>: String): String {
+    try {
+        <!UNREACHABLE_CODE!>throw<!> RuntimeException() //should be marked as unreachable, but is not
+    } finally {
+        throw NullPointerException()
+    }
+}