More precise diagnostics of smart cast impossible #KT-7240 Fixed

compiler/testData/diagnostics/tests/smartCasts/publicVals/customGetter.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 <!SMARTCAST_IMPOSSIBLE!>y<!>.length
         else
             return 0
     }

compiler/testData/diagnostics/tests/smartCasts/publicVals/delegate.kt

@@ -13,7 +13,7 @@ class Example {
 
     public fun foo(): String {
         // Smart cast is not possible if property is delegated
-        return if (p != null) <!TYPE_MISMATCH!>p<!> else ""
+        return if (p != null) <!SMARTCAST_IMPOSSIBLE!>p<!> else ""
     }
 
     public fun bar(): String {

compiler/testData/diagnostics/tests/smartCasts/publicVals/otherModule.kt

@@ -17,7 +17,7 @@ import a.X
 public fun X.gav(): Int {
     if (x != null)
         // Smart cast is not possible if definition is in another module
-        return x<!UNSAFE_CALL!>.<!>length
+        return <!SMARTCAST_IMPOSSIBLE!>x<!>.length
     else
         return 0
 }
@@ -29,7 +29,7 @@ package a
 public fun X.gav(): Int {
     if (x != null)
         // Even if it's in the same package
-        return x<!UNSAFE_CALL!>.<!>length
+        return <!SMARTCAST_IMPOSSIBLE!>x<!>.length
     else
         return 0
 }

compiler/testData/diagnostics/tests/smartCasts/publicVals/var.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 <!SMARTCAST_IMPOSSIBLE!>x<!>.length
         else if (y != null)
             // Even if they are private
-            return y<!UNSAFE_CALL!>.<!>length
+            return <!SMARTCAST_IMPOSSIBLE!>y<!>.length
         else
             return 0
     }