report 'ambiguity' on reference, not on the whole expression

as other type inference errors

compiler/testData/diagnostics/tests/scopes/AmbiguityBetweenRootAndPackage.kt

@@ -1,7 +1,7 @@
 // FILE: checkAmbiguityBetweenRootAndPackage.kt
 package test
 
-val t = <!OVERLOAD_RESOLUTION_AMBIGUITY!>testFun()<!>
+val t = <!OVERLOAD_RESOLUTION_AMBIGUITY!>testFun<!>()
 
 // FILE: checkAmbiguityBetweenRootAndPackageRoot.kt
 fun testFun() = 12

compiler/testData/diagnostics/tests/scopes/stopResolutionOnAmbiguity.kt

@@ -12,7 +12,7 @@ class C() {
 fun test(a : Any?) {
     if (a is B) {
         if (a is C) {
-            a.<!OVERLOAD_RESOLUTION_AMBIGUITY!>bar()<!>;
+            a.<!OVERLOAD_RESOLUTION_AMBIGUITY!>bar<!>();
         }
     }
 }