last stdlib cleanups

lib/core/allocators.nim

@@ -7,6 +7,8 @@
 #    distribution, for details about the copyright.
 #
 
+## Unstable API.
+
 type
   AllocatorFlag* {.pure.} = enum  ## flags describing the properties of the allocator
     ThreadLocal ## the allocator is thread local only.

lib/core/hotcodereloading.nim

@@ -1,3 +1,14 @@
+#
+#
+#            Nim's Runtime Library
+#        (c) Copyright 2019 Nim contributors
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## Unstable API.
+
 when defined(hotcodereloading):
   import
     macros