Allow use reference to reified type parameters in contracts since 1.4

compiler/testData/diagnostics/testsWithStdLib/contracts/smartcasts/reifiedGeneric.kt

@@ -0,0 +1,31 @@
+// !LANGUAGE: +AllowContractsForCustomFunctions +UseReturnsEffect +AllowReifiedGenericsInContracts
+// !USE_EXPERIMENTAL: kotlin.contracts.ExperimentalContracts
+// !DIAGNOSTICS: -INVISIBLE_REFERENCE -INVISIBLE_MEMBER -UNUSED_VARIABLE
+
+import kotlin.contracts.*
+
+inline fun <reified T> requireIsInstance(value: Any?) {
+    contract {
+        returns() implies (value is T)
+    }
+    if (value !is T) {
+        throw IllegalArgumentException()
+    }
+}
+
+inline fun <reified T> cast(value: Any?): T {
+    contract {
+        returns() implies (value is T)
+    }
+    return value as T
+}
+
+fun test_1(x: Any) {
+    requireIsInstance<String>(x)
+    <!DEBUG_INFO_SMARTCAST!>x<!>.length
+}
+
+fun test_2(x: Any) {
+    val s: String = cast(x)
+    <!DEBUG_INFO_SMARTCAST!>x<!>.length
+}