Fuchsia: Add C++ demangle to the native symbol resolver

runtime/vm/native_symbol_fuchsia.cc

Index: runtime/vm/native_symbol_fuchsia.cc
diff --git a/runtime/vm/native_symbol_fuchsia.cc b/runtime/vm/native_symbol_fuchsia.cc
index 084c00b54eefda1b08e1294fe9fe5af35ea5b5b5..22db3f72f4e1590aea492b67680b425b607c7fbc 100644
--- a/runtime/vm/native_symbol_fuchsia.cc
+++ b/runtime/vm/native_symbol_fuchsia.cc
@@ -2,11 +2,13 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-#include "platform/globals.h"
+#include "vm/globals.h"
 #if defined(TARGET_OS_FUCHSIA)
 
+#include "platform/memory_sanitizer.h"
 #include "vm/native_symbol.h"
 
+#include <cxxabi.h>  // NOLINT
 #include <dlfcn.h>  // NOLINT
 
 namespace dart {
@@ -31,6 +33,13 @@ char* NativeSymbolResolver::LookupSymbolName(uintptr_t pc, uintptr_t* start) {
   if (start != NULL) {
     *start = reinterpret_cast<uintptr_t>(info.dli_saddr);
   }
+  int status = 0;
+  size_t len = 0;
+  char* demangled = abi::__cxa_demangle(info.dli_sname, NULL, &len, &status);
+  MSAN_UNPOISON(demangled, len);
+  if (status == 0) {
+    return demangled;
+  }
   return strdup(info.dli_sname);
 }