Serialize and deserialize 'header' modifier for descriptors

This fixes KT-17001 because now 'header' modifier is loaded correctly
for deserialized members and the standard disambiguation in
OverloadingConflictResolver.compareCallsByUsedArguments takes place,
where header members are discriminated against the corresponding impl
members

 #KT-17001 Fixed

core/descriptor.loader.java/src/org/jetbrains/kotlin/load/kotlin/JvmMetadataVersion.kt

@@ -29,7 +29,7 @@ class JvmMetadataVersion(vararg numbers: Int) : BinaryVersion(*numbers) {
 
     companion object {
         @JvmField
-        val INSTANCE = JvmMetadataVersion(1, 1, 5)
+        val INSTANCE = JvmMetadataVersion(1, 1, 6)
 
         @JvmField
         val INVALID_VERSION = JvmMetadataVersion()