- fix some cases where we are using uninitialized memory

runtime/bin/dartutils.cc

Index: runtime/bin/dartutils.cc
diff --git a/runtime/bin/dartutils.cc b/runtime/bin/dartutils.cc
index e7237641bb8d0b94897ea46d154758fed0e3f50b..1415cb1750f5946497735fe851ed9c5dbd294969 100644
--- a/runtime/bin/dartutils.cc
+++ b/runtime/bin/dartutils.cc
@@ -18,6 +18,7 @@
 
 #include "platform/assert.h"
 #include "platform/globals.h"
+#include "platform/memory_sanitizer.h"
 
 // Return the error from the containing function if handle is in error handle.
 #define RETURN_IF_ERROR(handle)                                                \
@@ -927,6 +928,7 @@ Dart_Handle DartUtils::NewError(const char* format, ...) {
   va_end(args);
 
   char* buffer = reinterpret_cast<char*>(Dart_ScopeAllocate(len + 1));
+  MSAN_UNPOISON(buffer, (len + 1));
   va_list args2;
   va_start(args2, format);
   vsnprintf(buffer, (len + 1), format, args2);