[FIR] KT-56877: Allow referencing implicit receivers in class contracts

compiler/testData/diagnostics/testsWithStdLib/contracts/dsl/callUsualContractFunction.fir.kt

@@ -1,42 +0,0 @@
-// !DIAGNOSTICS: -UNUSED_PARAMETER
-
-package my
-
-// Accepts block, can't be distinguished from kotlin.contract without resolve
-fun contract(block: () -> Unit) {}
-
-// Accepts int, potentially can be distinguished from kotlin.contract by PSI,
-// but as of Kotlin 1.3.0, we don't do that
-fun contract(i: Int) {}
-
-fun doStuff() {}
-
-class SomeClass {
-
-    fun contract() {}
-
-    fun callMemberContractWithThis() {
-        this.contract()
-    }
-
-    fun callMemberContractWithoutThis() {
-        <!NONE_APPLICABLE!>contract<!>()
-    }
-
-    fun callTopLevelSamePsiInMember() {
-        contract { }
-    }
-}
-
-fun callTopLevelSamePsi() {
-    contract { }
-}
-
-fun callTopLevelDifferentPsi() {
-    contract(42)
-}
-
-fun callTopLevelSamePsiNotFirstStatement() {
-    doStuff()
-    contract { }
-}

compiler/testData/diagnostics/testsWithStdLib/contracts/dsl/callUsualContractFunction.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !DIAGNOSTICS: -UNUSED_PARAMETER
 
 package my

compiler/testData/diagnostics/testsWithStdLib/contracts/dsl/errors/accessToOuterThis.fir.kt

@@ -10,13 +10,13 @@ class Foo {
     inner class Bar {
         fun good() {
             contract {
-                <!ERROR_IN_CONTRACT_DESCRIPTION!>returns() implies (this<!UNRESOLVED_LABEL!>@Bar<!> != null)<!>
+                <!ERROR_IN_CONTRACT_DESCRIPTION!>returns() implies (this@Bar != null)<!>
             }
         }
 
         fun badOuter() {
             contract {
-                <!ERROR_IN_CONTRACT_DESCRIPTION!>returns() implies (this<!UNRESOLVED_LABEL!>@Foo<!> != null)<!>
+                <!ERROR_IN_CONTRACT_DESCRIPTION!>returns() implies (this@Foo != null)<!>
             }
         }
 
@@ -34,7 +34,7 @@ class Foo {
 
         fun A?.badWithReceiver() {
             contract {
-                <!ERROR_IN_CONTRACT_DESCRIPTION!>returns() implies (this<!UNRESOLVED_LABEL!>@Bar<!> != null)<!>
+                <!ERROR_IN_CONTRACT_DESCRIPTION!>returns() implies (this@Bar != null)<!>
             }
         }
     }

compiler/testData/diagnostics/testsWithStdLib/contracts/dsl/errors/referenceToProperty.1.3.fir.kt

@@ -7,7 +7,7 @@ import kotlin.contracts.*
 class Foo(val x: Int?) {
     fun isXNull(): Boolean {
         contract {
-            <!ERROR_IN_CONTRACT_DESCRIPTION!>returns(false) implies (<!UNRESOLVED_REFERENCE!>x<!> != null)<!>
+            <!ERROR_IN_CONTRACT_DESCRIPTION!>returns(false) implies (x != null)<!>
         }
         return x != null
     }

compiler/testData/diagnostics/testsWithStdLib/contracts/dsl/errors/referenceToProperty.1.4.fir.kt

@@ -7,8 +7,8 @@ import kotlin.contracts.*
 class Foo(val x: Int?) {
     fun isXNull(): Boolean {
         contract {
-            <!ERROR_IN_CONTRACT_DESCRIPTION!>returns(false) implies (<!UNRESOLVED_REFERENCE!>x<!> != null)<!>
+            <!ERROR_IN_CONTRACT_DESCRIPTION!>returns(false) implies (x != null)<!>
         }
         return x != null
     }
-}
+}