More work on moving engine into dlmalloc heap

luprex/core/cpp/printbuffer.cpp

@@ -1,11 +1,11 @@
-#include "wrap-algorithm.hpp"
 #include "wrap-sstream.hpp"
 
 #include "printbuffer.hpp"
 
+#include <algorithm>
 #include <cstdio>
 
-struct PrintBufferCore {
+struct PrintBufferCore  : public eng::heap {
     // The most recent lines printed.
     eng::deque<eng::string> lines_;
 
@@ -176,7 +176,7 @@ void PrintBuffer::patch(StreamBuffer *sb, DebugCollector *dbc) {
     }
 }
 
-bool PrintChanneler::channel(const PrintBuffer *printbuffer, eng::ostream &ostream) {
+bool PrintChanneler::channel(const PrintBuffer *printbuffer, std::ostream &ostream) {
     if (printbuffer == nullptr) return false;
     if (printbuffer->first_line() > line_) {
         line_ = printbuffer->first_line();