Support for new double colon expressions in type checker

Despite the fact that the LHS of a double colon expression is now KtExpression
instead of KtUserType, we must still consider it a type for callable references
to work. Extract and reuse relevant parts of QualifiedExpressionResolver and
TypeResolver to support this behavior

compiler/testData/diagnostics/tests/callableReference/classVsPackage.kt

@@ -0,0 +1,24 @@
+// MODULE: m1
+// FILE: 1.kt
+
+package a
+
+class b {
+    class c
+}
+
+// MODULE: m2
+// FILE: 2.kt
+
+package a.b
+
+class c {
+    fun foo() {}
+}
+
+// MODULE: m3(m1, m2)
+// FILE: test.kt
+
+package test
+
+fun test() = a.b.c::foo

compiler/testData/diagnostics/tests/callableReference/classVsPackage.txt

@@ -0,0 +1,61 @@
+// -- Module: <m1> --
+package
+
+package a {
+
+    public final class b {
+        public constructor b()
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+
+        public final class c {
+            public constructor c()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+}
+
+
+// -- Module: <m2> --
+package
+
+package a {
+
+    package a.b {
+
+        public final class c {
+            public constructor c()
+            public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+            public final fun foo(): kotlin.Unit
+            public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+            public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+        }
+    }
+}
+
+
+// -- Module: <m3> --
+package
+
+package a {
+
+    public final class b {
+        // -- Module: <m1> --
+    }
+
+    package a.b {
+
+        public final class c {
+            // -- Module: <m2> --
+        }
+    }
+}
+
+package test {
+    public fun test(): kotlin.reflect.KFunction1<a.b.c, kotlin.Unit>
+}
+
+

compiler/testData/diagnostics/tests/callableReference/packageInLhs.kt

@@ -0,0 +1,16 @@
+// !DIAGNOSTICS: -UNUSED_EXPRESSION
+// FILE: simpleName.kt
+
+package foo
+
+fun test() {
+    <!UNRESOLVED_REFERENCE!>foo<!>::test
+}
+
+// FILE: qualifiedName.kt
+
+package foo.bar
+
+fun test() {
+    foo.<!UNRESOLVED_REFERENCE!>bar<!>::test
+}

compiler/testData/diagnostics/tests/callableReference/packageInLhs.txt

@@ -0,0 +1,9 @@
+package
+
+package foo {
+    public fun test(): kotlin.Unit
+
+    package foo.bar {
+        public fun test(): kotlin.Unit
+    }
+}

compiler/testData/diagnostics/tests/callableReference/parsingPriorityOfGenericArgumentsVsLess.kt

@@ -0,0 +1,9 @@
+package test
+
+class Foo {
+    fun <T> bar(x: Int) = x
+}
+
+fun test() {
+    Foo::<!TYPE_INFERENCE_NO_INFORMATION_FOR_PARAMETER!>bar<!> <!SYNTAX!>< <!DEBUG_INFO_MISSING_UNRESOLVED!>Int<!> ><!> <!SYNTAX!>(2 <!DEBUG_INFO_MISSING_UNRESOLVED!>+<!> 2)<!>
+}

compiler/testData/diagnostics/tests/callableReference/parsingPriorityOfGenericArgumentsVsLess.txt

@@ -0,0 +1,13 @@
+package
+
+package test {
+    public fun test(): kotlin.Unit
+
+    public final class Foo {
+        public constructor Foo()
+        public final fun </*0*/ T> bar(/*0*/ x: kotlin.Int): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+        public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+        public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    }
+}

compiler/testData/diagnostics/tests/callableReference/whitespacesInExpression.kt

@@ -0,0 +1,16 @@
+// !CHECK_TYPE
+
+class Foo
+
+fun Foo?.bar() {}
+
+fun test() {
+    val r1 = Foo ?:: bar
+    checkSubtype<(Foo?) -> Unit>(r1)
+
+    val r2 = Foo ? :: bar
+    checkSubtype<(Foo?) -> Unit>(r2)
+
+    val r3 = Foo ? ? :: bar
+    checkSubtype<(Foo?) -> Unit>(r3)
+}

compiler/testData/diagnostics/tests/callableReference/whitespacesInExpression.txt

@@ -0,0 +1,11 @@
+package
+
+public fun test(): kotlin.Unit
+public fun Foo?.bar(): kotlin.Unit
+
+public final class Foo {
+    public constructor Foo()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}