Reflection: adjust type definitions for ConcurrentHashMap

Adjust the types of `ConcurrentHashMap` to match the implementation.  This field is always a `uint32_t`, which would be misread previously.  Thanks to @mikeash for helping identify this.

Author: compnerd

include/swift/Reflection/RuntimeInternals.h

@@ -49,8 +49,8 @@ template <typename Runtime> struct MetadataCacheNode {
 };
 
 template <typename Runtime> struct ConcurrentHashMap {
-  typename Runtime::StoredSize ReaderCount;
-  typename Runtime::StoredSize ElementCount;
+  typename uint32_t ReaderCount;
+  typename uint32_t ElementCount;
   typename Runtime::StoredPointer Elements;
   typename Runtime::StoredPointer Indices;
   // We'll ignore the remaining fields for now....