Restore implicit wildcard types

The Kotlin compiler represents types like List<out CharSequence> internally as List<CharSequence> due to the fact that List's type parameter is covariant, and similarly Comparable<in CharSequence> where Comparable's type parameter is contravariant. However it restores use-site variance when emitting class files, so we must do the same thing for
compatability with Java code.

Note this is a partial solution because it will also add wildcards to Java .class files that *could* have a variance / wildcard but don't -- for example, a Java method could really take an invariant Comparable<CharSequence>, which is only achievable in Kotlin via the @JvmSuppressWildcards annotation. We also don't yet support
@JvmSuppressWildcards given on a surrounding class or function.

java/kotlin-extractor/src/main/kotlin/KotlinFileExtractor.kt

@@ -497,7 +497,9 @@ open class KotlinFileExtractor(
                 else
                     null
             } ?: vp.type
-            val substitutedType = typeSubstitution?.let { it(maybeErasedType, TypeContext.OTHER, pluginContext) } ?: maybeErasedType
+            val typeWithWildcards = addJavaLoweringWildcards(maybeErasedType, true)
+            val substitutedType = typeSubstitution?.let { it(typeWithWildcards, TypeContext.OTHER, pluginContext) } ?: typeWithWildcards
+
             val id = useValueParameter(vp, parent)
             if (extractTypeAccess) {
                 extractTypeAccessRecursive(substitutedType, location, id, -1)
@@ -704,7 +706,7 @@ open class KotlinFileExtractor(
 
                 val paramsSignature = allParamTypes.joinToString(separator = ",", prefix = "(", postfix = ")") { it.javaResult.signature!! }
 
-                val adjustedReturnType = getAdjustedReturnType(f)
+                val adjustedReturnType = addJavaLoweringWildcards(getAdjustedReturnType(f), false)
                 val substReturnType = typeSubstitution?.let { it(adjustedReturnType, TypeContext.RETURN, pluginContext) } ?: adjustedReturnType
 
                 val locId = locOverride ?: getLocation(f, classTypeArgsIncludingOuterClasses)