Add few tests for contracts

- Contracts in getter/setter (unexpected behaviour)
- Check smartcasts when non-null assertion for a contract function is used
- Check work of contracts when type parameter of the callsInPlace is specify explicitly
- Check smartcasts working if type checking for contract function is used

compiler/tests-spec/testData/diagnostics/notLinked/contracts/declarations/contractFunction/neg/4.kt

@@ -0,0 +1,64 @@
+// !LANGUAGE: +AllowContractsForCustomFunctions +UseCallsInPlaceEffect
+// !DIAGNOSTICS: -INVISIBLE_REFERENCE -INVISIBLE_MEMBER -UNUSED_PARAMETER
+// !USE_EXPERIMENTAL: kotlin.contracts.ExperimentalContracts
+
+/*
+ KOTLIN DIAGNOSTICS NOT LINKED SPEC TEST (NEGATIVE)
+
+ SECTION: contracts
+ CATEGORIES: declarations, contractFunction
+ NUMBER: 4
+ DESCRIPTION: Check that fun with contract and CallsInPlace effect is an inline function.
+ UNEXPECTED BEHAVIOUR
+ ISSUES: KT-27090
+ */
+
+import kotlin.contracts.*
+
+val Boolean.case_1: () -> Unit
+    get() {
+        contract {
+            returns() implies (this@case_1)
+        }
+        return {}
+    }
+
+val (() -> Unit).case_2: () -> Unit
+    get() {
+        contract {
+            callsInPlace(this@case_2, InvocationKind.EXACTLY_ONCE)
+        }
+        return {}
+    }
+
+var Boolean.case_3: () -> Unit
+    get() {
+        return {}
+    }
+    set(value) {
+        contract {
+            callsInPlace(value, InvocationKind.EXACTLY_ONCE)
+        }
+    }
+
+var (() -> Unit).case_4: () -> Unit
+    get() {
+        return {}
+    }
+    set(value) {
+        contract {
+            callsInPlace(this@case_4, InvocationKind.EXACTLY_ONCE)
+        }
+    }
+
+val Boolean.case_5: () -> Unit
+    get() {
+        contract {
+            returns() implies (this@case_5)
+        }
+
+        if (!this@case_5)
+            throw Exception()
+
+        return {}
+    }

compiler/tests-spec/testData/diagnostics/notLinked/contracts/declarations/contractFunction/neg/4.txt

@@ -0,0 +1,7 @@
+package
+
+public val kotlin.Boolean.case_1: () -> kotlin.Unit
+public val (() -> kotlin.Unit).case_2: () -> kotlin.Unit
+public var kotlin.Boolean.case_3: () -> kotlin.Unit
+public var (() -> kotlin.Unit).case_4: () -> kotlin.Unit
+public val kotlin.Boolean.case_5: () -> kotlin.Unit