Qualifier no longer defers "(nested) class vs package" resolution.

Consider FQN 'a.b.c'.
If 'a' is a classifier in the current scope,
    resolve rest in the corresponding class scope.
Otherwise (if 'a' is a package),
    find the maximum possible prefix 'a.b' resolving to a package,
    resolve rest in the corresponding package scope.

compiler/testData/diagnostics/tests/imports/TopLevelClassVsPackage.kt

@@ -46,7 +46,7 @@ fun test2(_a: a) {
     _ab._ab()
 
     val _ab2 = a.b()
-    _ab2.<!UNRESOLVED_REFERENCE!>_ab<!>() // todo
+    _ab2._ab()
 
     _fun()
 }
@@ -62,7 +62,7 @@ fun test3(_a: a) {
     _ab._ab()
 
     val _ab2 = a.b()
-    _ab2.<!UNRESOLVED_REFERENCE!>_ab<!>() // todo
+    _ab2._ab()
 
     _fun()
 }

compiler/testData/diagnostics/tests/qualifiedExpression/GenericClassVsPackage.kt

@@ -30,9 +30,10 @@ fun test(ab_c: c) {
     ab_c3.ab_c()
 }
 
-fun test2(a_bc: a.b.c) {
-    a_bc.<!UNRESOLVED_REFERENCE!>a_bc<!>() // todo
-    a_bc.ab_c() // todo
+// NB according to the maximum package prefix rule, 'a.b.c' denotes 'c' in package 'a.b' (thus ab_c, not a_bc)
+fun test2(ab_c: a.b.c) {
+    ab_c.<!UNRESOLVED_REFERENCE!>a_bc<!>()
+    ab_c.ab_c()
 }
 
 
@@ -66,7 +67,7 @@ fun test(a_b: b) {
     _ab._ab()
 
     val _ab2 = a.b()
-    _ab2.<!UNRESOLVED_REFERENCE!>_ab<!>() // todo
+    _ab2._ab()
 }
 
 fun test2(_ab: a.b) {

compiler/testData/diagnostics/tests/qualifiedExpression/GenericClassVsPackage.txt

@@ -42,7 +42,7 @@ package a {
 package
 
 public fun test(/*0*/ ab_c: a.b.c): kotlin.Unit
-public fun test2(/*0*/ a_bc: a.b.c): kotlin.Unit
+public fun test2(/*0*/ ab_c: a.b.c): kotlin.Unit
 
 package a {
 
@@ -110,3 +110,5 @@ package a {
         // -- Module: <top_m1> --
     }
 }
+
+

compiler/testData/diagnostics/tests/qualifiedExpression/PackageVsClass2.kt

@@ -0,0 +1,15 @@
+// MODULE: m1
+// FILE: a.kt
+package a
+
+class b {
+    fun a_b() {}
+}
+
+// MODULE: m2(m1)
+// FILE: b.kt
+package test
+
+class a
+
+val x = a.<!UNRESOLVED_REFERENCE!>b<!>()

compiler/testData/diagnostics/tests/qualifiedExpression/PackageVsClass2.txt

@@ -0,0 +1,37 @@
+// -- Module: <m1> --
+package
+
+package a {
+
+    public final class b {
+        public constructor b()
+        public final fun a_b(): kotlin.Unit
+        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 {
+
+    public final class b {
+        // -- Module: <m1> --
+    }
+}
+
+package test {
+    public val x: [ERROR : Type for a.b()]
+
+    public final class a {
+        public constructor a()
+        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/qualifiedExpression/PackageVsRootClass.kt

@@ -40,5 +40,5 @@ fun test(_ab: a.b) {
     _ab._ab()
 
     val _ab2 = a.b()
-    _ab2.<!UNRESOLVED_REFERENCE!>_ab<!>() // todo
+    _ab2._ab() // todo
 }

compiler/testData/diagnostics/tests/qualifiedExpression/visibleClassVsQualifiedClass.kt

@@ -25,10 +25,10 @@ class a {}
 fun test(a_: a.<!UNRESOLVED_REFERENCE!>b<!>) {
     <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>a_<!>.<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>a_b<!>()
 
-    val a_2 = a.b()
-    a_2.a_b() // todo: must be unresolved
-    a_2.<!UNRESOLVED_REFERENCE!>some_ab<!>()
-    a_2.<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>a_()<!>
+    val a_2 = a.<!UNRESOLVED_REFERENCE!>b<!>()
+    <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>a_2<!>.<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>a_b<!>()
+    <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>a_2<!>.<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>some_ab<!>()
+    <!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>a_2<!>.<!DEBUG_INFO_ELEMENT_WITH_ERROR_TYPE!>a_<!>()
 }
 
 // FILE: c2.kt
@@ -44,7 +44,7 @@ fun test(_ab: a.b) {
     _ab.other2_ab()
 
     val _ab2 = a.b()
-    _ab2.<!UNRESOLVED_REFERENCE!>other2_ab<!>() // todo
+    _ab2.other2_ab()
 }
 
 // FILE: c3.kt
@@ -54,5 +54,5 @@ fun test(_ab: a.b) {
     _ab.some_ab()
 
     val _ab2 = a.b()
-    _ab2.<!UNRESOLVED_REFERENCE!>some_ab<!>() // todo
+    _ab2.some_ab()
 }