[FIR] Add NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY diagnostic

compiler/testData/diagnostics/tests/smartCasts/kt3899.fir.kt

@@ -3,7 +3,7 @@ data class StringPair(val first: String, val second: String)
 infix fun String.to(second: String) = StringPair(this, second)
 
 fun hashMapOf(pair: StringPair): MutableMap<String, String> {
-}
+<!NO_RETURN_IN_FUNCTION_WITH_BLOCK_BODY!>}<!>
 
 fun F() : MutableMap<String, String> {
     val value: String? = "xyz"