FIR: report UNSAFE_CALL on dot when possible

compiler/testData/diagnostics/tests/smartCasts/publicVals/customGetter.fir.kt

@@ -5,7 +5,7 @@ public class X {
     public fun fn(): Int {
         if (y != null)
             // With non-default getter smartcast is not possible
-            return y.<!UNSAFE_CALL!>length<!>
+            return y<!UNSAFE_CALL!>.<!>length
         else
             return 0
     }

compiler/testData/diagnostics/tests/smartCasts/publicVals/var.fir.kt

@@ -4,10 +4,10 @@ public class X {
     public fun fn(): Int {
         if (x != null)
             // Smartcast is not possible for variable properties
-            return x.<!UNSAFE_CALL!>length<!>
+            return x<!UNSAFE_CALL!>.<!>length
         else if (y != null)
             // Even if they are private
-            return y.<!UNSAFE_CALL!>length<!>
+            return y<!UNSAFE_CALL!>.<!>length
         else
             return 0
     }