FIR: initial support of suspend conversion for function reference

compiler/testData/diagnostics/tests/suspendConversion/suspendConversionCompatibility.fir.kt

@@ -22,7 +22,7 @@ object Test2 {
 
         fun test() {
             val result = foo(::bar)
-            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.Int")!>result<!>
+            <!DEBUG_INFO_EXPRESSION_TYPE("kotlin.String")!>result<!>
         }
     }
 }