Remove many features when building product mode

runtime/vm/disassembler.cc

Index: runtime/vm/disassembler.cc
diff --git a/runtime/vm/disassembler.cc b/runtime/vm/disassembler.cc
index 99b13ce4bb29afcd9145c2ad30e11701a15c51f2..927a317fa0b385994cb6dbb641599e159d4e31d8 100644
--- a/runtime/vm/disassembler.cc
+++ b/runtime/vm/disassembler.cc
@@ -44,6 +44,8 @@ void DisassembleToStdout::Print(const char* format, ...) {
 }
 
 
+#ifndef PRODUCT
+
 void DisassembleToJSONStream::ConsumeInstruction(const Code& code,
                                                  char* hex_buffer,
                                                  intptr_t hex_size,
@@ -91,6 +93,7 @@ void DisassembleToJSONStream::Print(const char* format, ...) {
   free(p);
 }
 
+#endif  // !PRODUCT
 
 class FindAddrVisitor : public FindObjectVisitor {
  public: