[FIR] Report VAL_REASSIGNMENT on assign to non-local vals

In this commit reporting on member properties in init section of class
  is not supported (see KT-55528)

^KT-55493 Fixed

compiler/testData/diagnostics/tests/controlFlowAnalysis/kt607.fir.kt

@@ -8,8 +8,8 @@ fun foo(a: A) {
            get() = 42
     }
 
-    a.z = 23
-    o.y = 11   //Should be an error here
+    a.<!VAL_REASSIGNMENT!>z<!> = 23
+    o.<!VAL_REASSIGNMENT!>y<!> = 11   //Should be an error here
 }
 
 class A() {