Introduce PureReifiable annotation

It prevents reporting unsafe substitution warning on expressions
like 'arrayOf(arrayOf(""))'

compiler/testData/diagnostics/testsWithStdLib/pureReifiable.kt

@@ -0,0 +1,12 @@
+// !DIAGNOSTICS: -UNUSED_PARAMETER
+
+@Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+inline fun <reified @kotlin.internal.PureReifiable T> foo(x: T) {}
+
+fun test() {
+    foo<List<String>>(listOf(""))
+    foo(listOf(""))
+
+    foo<Array<String>>(arrayOf(""))
+    foo(arrayOf(""))
+}