Implement KTypeProjection.toString

The implementation is checked by tests on typeOf.

 #KT-30071 Fixed

libraries/stdlib/jvm/runtime/kotlin/jvm/internal/TypeReference.kt

@@ -8,7 +8,6 @@ package kotlin.jvm.internal
 import kotlin.reflect.*
 
 @SinceKotlin("1.4")
-@Suppress("NEWER_VERSION_IN_SINCE_KOTLIN", "API_NOT_AVAILABLE" /* See KT-30129 */) // TODO: remove this in 1.4
 public class TypeReference(
     override val classifier: KClassifier,
     override val arguments: List<KTypeProjection>,
@@ -55,8 +54,8 @@ public class TypeReference(
             else -> "kotlin.Array"
         }
 
-    // TODO: this should be the implementation of KTypeProjection.toString, see KT-30071
-    @Suppress("NO_REFLECTION_IN_CLASS_PATH")
+    // This is based on KTypeProjection.toString, but uses [asString] to avoid adding the
+    // "reflection not supported" suffix to each type argument.
     private fun KTypeProjection.asString(): String {
         if (variance == null) return "*"
 

libraries/stdlib/src/kotlin/reflect/KType.kt

@@ -71,6 +71,13 @@ public data class KTypeProjection constructor(
      */
     public val type: KType?
 ) {
+    override fun toString(): String = when (variance) {
+        null -> "*"
+        KVariance.INVARIANT -> type.toString()
+        KVariance.IN -> "in $type"
+        KVariance.OUT -> "out $type"
+    }
+
     public companion object {
         /**
          * Star projection, denoted by the `*` character.