add back map for profiling

Author: SteveBronder

stan/math/prim/err/check_flag_sundials.hpp

@@ -16,7 +16,7 @@ namespace math {
 
 /**
  * Map cvodes error flag to acutally error msg. The most frequent
- * errors are put at the top. An alternative would be to use std::unordered_map
+ * errors are put at the top. An alternative would be to use std::map
  * but in our case the difference would be negligible. Note that we
  * don't use CVGetReturnFlagName function to retrieve the constant
  * because sanitizer indicates it contains mem leak.

stan/math/rev/core/profiling.hpp

@@ -115,7 +115,7 @@ class profile_info {
 
 using profile_key = std::pair<std::string, std::thread::id>;
 
-using profile_map = std::unordered_map<profile_key, profile_info>;
+using profile_map = std::map<profile_key, profile_info>;
 
 /**
  * Profiles C++ lines where the object is in scope.