FIR: Refine callable reference resolution in assignment position

synthetic_select<() -> T>(::foo) form allows to select better candidate
than synthetic_select(::foo) with expect type `() -> T`

compiler/tests-spec/testData/diagnostics/linked/overload-resolution/resolving-callable-references/resolving-callable-references-not-used-as-arguments-to-a-call/p-1/neg/1.1.fir.kt

@@ -17,11 +17,11 @@ class Case1() {
 
 }
 fun case1() {
-    val y0: (String)-> Case1 = ::foo
-    val y1: (String)-> Case1 = Case1.Companion::foo
-    val y2: (String)-> Case1 = (Case1)::foo
+    val y0: (String)-> Case1 = ::<!UNRESOLVED_REFERENCE!>foo<!>
+    val y1: (String)-> Case1 = Case1.Companion::<!UNRESOLVED_REFERENCE!>foo<!>
+    val y2: (String)-> Case1 = (Case1)::<!UNRESOLVED_REFERENCE!>foo<!>
 }
 
-fun case1_0() : (String)-> Case1 = ::foo
-fun case1_1() : (String)-> Case1 = (Case1)::foo
-fun case1_2(): (String)-> Case1 = Case1.Companion::foo
+fun case1_0() : (String)-> Case1 = ::<!UNRESOLVED_REFERENCE!>foo<!>
+fun case1_1() : (String)-> Case1 = (Case1)::<!UNRESOLVED_REFERENCE!>foo<!>
+fun case1_2(): (String)-> Case1 = Case1.Companion::<!UNRESOLVED_REFERENCE!>foo<!>

compiler/tests-spec/testData/diagnostics/linked/overload-resolution/resolving-callable-references/resolving-callable-references-not-used-as-arguments-to-a-call/p-1/pos/1.2.fir.kt

@@ -11,7 +11,7 @@ import libCase1.*
 import kotlin.text.format
 
 fun case1() {
-    val y2 : () ->String =(String)::<!UNRESOLVED_REFERENCE!>format<!>
+    val y2 : () ->String =(String)::format
 }
 
 // FILE: LibCase1.kt

compiler/tests-spec/testData/diagnostics/linked/overload-resolution/resolving-callable-references/resolving-callable-references-not-used-as-arguments-to-a-call/p-1/pos/1.3.fir.kt

@@ -11,7 +11,7 @@ package testsCase1
 class Case() {
     fun case(v: V) {
         // InitializertTypeCheckerMismatch bug
-        val va: () -> String = <!INITIALIZER_TYPE_MISMATCH!>(V)::a<!>
+        val va: () -> String = (V)::a
 
         val vb: () -> String = (V)::b