[NI] Report not-a-class LHS error for callable reference arguments

^KT-37531 Fixed

compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/tower/PSICallResolver.kt

@@ -745,7 +745,13 @@ class PSICallResolver(
             is DoubleColonLHS.Type -> {
                 val qualifiedExpression = ktExpression.receiverExpression!!
                 val qualifier = expressionTypingContext.trace.get(BindingContext.QUALIFIER, qualifiedExpression)
-                LHSResult.Type(qualifier, lhsResult.type.unwrap())
+                val classifier = lhsResult.type.constructor.declarationDescriptor
+                if (classifier !is ClassDescriptor) {
+                    expressionTypingContext.trace.report(Errors.CALLABLE_REFERENCE_LHS_NOT_A_CLASS.on(ktExpression))
+                    LHSResult.Error
+                } else {
+                    LHSResult.Type(qualifier, lhsResult.type.unwrap())
+                }
             }
         }
 

compiler/testData/diagnostics/tests/callableReference/function/lhsNotAClass.fir.kt

@@ -1,9 +1,19 @@
+// !WITH_NEW_INFERENCE
+
 class A<T, U : Any> {
     fun foo() = <!OTHER_ERROR!>T<!>::toString
 
     fun bar() = <!OTHER_ERROR!>U<!>::toString
+
+    fun baz() {
+        take(<!OTHER_ERROR!>T<!>::toString)
+
+        take(<!OTHER_ERROR!>U<!>::toString)
+    }
 }
 
 fun <T> foo() = <!OTHER_ERROR!>T<!>::toString
 
 fun <U : Any> bar() = <!OTHER_ERROR!>U<!>::toString
+
+fun take(arg: Any) {}

compiler/testData/diagnostics/tests/callableReference/function/lhsNotAClass.kt

@@ -1,9 +1,19 @@
+// !WITH_NEW_INFERENCE
+
 class A<T, U : Any> {
     fun foo() = <!CALLABLE_REFERENCE_LHS_NOT_A_CLASS!>T::<!UNRESOLVED_REFERENCE!>toString<!><!>
 
     fun bar() = <!CALLABLE_REFERENCE_LHS_NOT_A_CLASS!>U::<!UNRESOLVED_REFERENCE!>toString<!><!>
+
+    fun baz() {
+        take(<!CALLABLE_REFERENCE_LHS_NOT_A_CLASS, OI;CALLABLE_REFERENCE_LHS_NOT_A_CLASS, OI;CALLABLE_REFERENCE_LHS_NOT_A_CLASS!>T::<!OI;UNRESOLVED_REFERENCE!>toString<!><!>)
+
+        take(<!CALLABLE_REFERENCE_LHS_NOT_A_CLASS, OI;CALLABLE_REFERENCE_LHS_NOT_A_CLASS, OI;CALLABLE_REFERENCE_LHS_NOT_A_CLASS!>U::<!OI;UNRESOLVED_REFERENCE!>toString<!><!>)
+    }
 }
 
 fun <T> foo() = <!CALLABLE_REFERENCE_LHS_NOT_A_CLASS!>T::<!UNRESOLVED_REFERENCE!>toString<!><!>
 
 fun <U : Any> bar() = <!CALLABLE_REFERENCE_LHS_NOT_A_CLASS!>U::<!UNRESOLVED_REFERENCE!>toString<!><!>
+
+fun take(<!UNUSED_PARAMETER!>arg<!>: Any) {}

compiler/testData/diagnostics/tests/callableReference/function/lhsNotAClass.txt

@@ -2,10 +2,12 @@ package
 
 public fun </*0*/ U : kotlin.Any> bar(): [ERROR : Error function type]
 public fun </*0*/ T> foo(): [ERROR : Error function type]
+public fun take(/*0*/ arg: kotlin.Any): kotlin.Unit
 
 public final class A</*0*/ T, /*1*/ U : kotlin.Any> {
     public constructor A</*0*/ T, /*1*/ U : kotlin.Any>()
     public final fun bar(): [ERROR : Error function type]
+    public final fun baz(): kotlin.Unit
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
     public final fun foo(): [ERROR : Error function type]
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int