Fix narrowing conversion warnings on Windows. (#895)

Author: BillyONeal

Release/src/http/client/http_client_winhttp.cpp

@@ -1583,7 +1583,7 @@ class winhttp_client final : public _http_client_communicator
                     else if (length > p_request_context->m_remaining_to_write)
                     {
                         // The stream grew, but we won't
-                        length = p_request_context->m_remaining_to_write;
+                        length = static_cast<size_t>(p_request_context->m_remaining_to_write);
                     }
 
                     do_compress(pplx::task_from_result<size_t>(length)).then(after_read);

Release/src/http/common/http_msg.cpp

@@ -319,7 +319,7 @@ size_t http_msg_base::_get_stream_length()
         auto offset = stream.tell();
         auto end = stream.seek(0, std::ios_base::end);
         stream.seek(offset);
-        return static_cast<utility::size64_t>(end - offset);
+        return static_cast<size_t>(end - offset);
     }
 
     return std::numeric_limits<size_t>::max();