[FIR-TEST] Add new testdata generated after changes in previous commit

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

@@ -0,0 +1,20 @@
+// !LANGUAGE: +AllowContractsForCustomFunctions +UseReturnsEffect
+// !DIAGNOSTICS: -INVISIBLE_REFERENCE -INVISIBLE_MEMBER
+// !USE_EXPERIMENTAL: kotlin.contracts.ExperimentalContracts
+
+import kotlin.contracts.*
+
+fun test(x: Any?) {
+    if (isString(x)) {
+        x.<!UNRESOLVED_REFERENCE!>length<!>
+    }
+}
+
+fun isString(x: Any?): Boolean {
+    contract {
+        returns(true) implies (x is String)
+    }
+    return x is String
+}
+
+