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

as other type inference errors

compiler/frontend/src/org/jetbrains/jet/lang/resolve/calls/tasks/TracingStrategyImpl.java

@@ -143,7 +143,7 @@ public class TracingStrategyImpl implements TracingStrategy {
 
     @Override
     public <D extends CallableDescriptor> void ambiguity(@NotNull BindingTrace trace, @NotNull Collection<ResolvedCallWithTrace<D>> descriptors) {
-        trace.report(OVERLOAD_RESOLUTION_AMBIGUITY.on(call.getCallElement(), descriptors));
+        trace.report(OVERLOAD_RESOLUTION_AMBIGUITY.on(reference, descriptors));
     }
 
     @Override

compiler/testData/diagnostics/tests/AutocastAmbiguitites.kt

@@ -10,7 +10,7 @@ class C() {
 fun test(a : Any?) {
   if (a is B) {
       if (a is C) {
-          a.<!OVERLOAD_RESOLUTION_AMBIGUITY!>bar()<!>;
+          a.<!OVERLOAD_RESOLUTION_AMBIGUITY!>bar<!>();
       }
   }
 }

compiler/testData/diagnostics/tests/dataFlowInfoTraversal/IfThenElseBothInvalid.kt

@@ -6,11 +6,11 @@ fun foo() {
     bar(<!TYPE_MISMATCH!>x<!>)
     if (x != 2) {
         if (x == null) return
-        2+<!SYNTAX!><!>
+        2<!OVERLOAD_RESOLUTION_AMBIGUITY!>+<!><!SYNTAX!><!>
     }
     else {
         if (<!SENSELESS_COMPARISON!>x == null<!>) return
-        2+<!SYNTAX!><!>
+        2<!OVERLOAD_RESOLUTION_AMBIGUITY!>+<!><!SYNTAX!><!>
     }
     bar(x)
 }

compiler/testData/diagnostics/tests/j+k/ambiguousSamAdapters.kt

@@ -12,7 +12,7 @@ public class A {
 // FILE: test.kt
 
 fun main() {
-    A.<!OVERLOAD_RESOLUTION_AMBIGUITY!>foo { "Hello!" }<!>
+    A.<!OVERLOAD_RESOLUTION_AMBIGUITY!>foo<!> { "Hello!" }
     A.foo(Runnable { "Hello!" })
 }
 

compiler/testData/diagnostics/tests/operatorsOverloading/IteratorAmbiguity.kt

@@ -21,7 +21,7 @@ class MyIterator {
 class MyElement
 
 fun test1(collection: MyCollection) {
-    collection.<!OVERLOAD_RESOLUTION_AMBIGUITY!>iterator()<!>
+    collection.<!OVERLOAD_RESOLUTION_AMBIGUITY!>iterator<!>()
     for (element in <!ITERATOR_AMBIGUITY!>collection<!>) {
     }
 }

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<!>();
         }
     }
 }

compiler/testData/diagnostics/tests/varargs/AmbiguousVararg.kt

@@ -2,5 +2,5 @@ fun foo(vararg <!UNUSED_PARAMETER!>t<!> : String) = ""
 fun foo(vararg <!UNUSED_PARAMETER!>t<!> : Int) = ""
 
 fun test() {
-    <!OVERLOAD_RESOLUTION_AMBIGUITY!>foo()<!>
+    <!OVERLOAD_RESOLUTION_AMBIGUITY!>foo<!>()
 }

compiler/testData/diagnostics/tests/varargs/MostSepcificVarargsWithJava.kt

@@ -3,9 +3,9 @@ fun main(j : C, s : Array<String?>) {
     j.from()
     j.from("")
     j.from("", "")
-    j.<!OVERLOAD_RESOLUTION_AMBIGUITY!>from("", "", "")<!>
+    j.<!OVERLOAD_RESOLUTION_AMBIGUITY!>from<!>("", "", "")
 
-    j.<!OVERLOAD_RESOLUTION_AMBIGUITY!>from("", *s)<!> // This should not be an ambiguity, see KT-1842
+    j.<!OVERLOAD_RESOLUTION_AMBIGUITY!>from<!>("", *s) // This should not be an ambiguity, see KT-1842
     j.from(*s)
 }