Put report_error() back in a mutex

We may no longer need to wrap the ostream operations, but we still need
to wrap the test for whether report_error() is being called recursively.

Trying to just never call report_error() recursively would be doable for
the moment (the asserts inside `on_command_line` tests in `print_trace`
seem to be the only code path that can currently do it), but I don't see
a way to future proof that - we like to do lots of helpful things when
error reporting, and we like to fill the things we do with assertions.

Author: roystgnr

include/base/libmesh_common.h

@@ -390,7 +390,9 @@ struct casting_compare {
   do {                                                                  \
     std::stringstream message_stream;                                   \
     message_stream << msg << '\n';                                      \
+    libMesh::Threads::lock_singleton_spin_mutex();                      \
     libMesh::MacroFunctions::report_error(__FILE__, __LINE__, LIBMESH_DATE, LIBMESH_TIME, message_stream); \
+    libMesh::Threads::unlock_singleton_spin_mutex();                    \
     LIBMESH_THROW(libMesh::LogicError(message_stream.str()));           \
   } while (0)
 
@@ -418,7 +420,9 @@ struct casting_compare {
   do {                                                                  \
     std::stringstream message_stream;                                   \
     message_stream << msg << '\n';                                      \
+    libMesh::Threads::lock_singleton_spin_mutex();                      \
     libMesh::MacroFunctions::report_error(__FILE__, __LINE__, LIBMESH_DATE, LIBMESH_TIME, message_stream); \
+    libMesh::Threads::unlock_singleton_spin_mutex();                    \
     LIBMESH_THROW(libMesh::NotImplemented(message_stream.str()));       \
   } while (0)
 
@@ -428,7 +432,9 @@ struct casting_compare {
   do {                                                                  \
     std::stringstream message_stream;                                   \
     message_stream << msg << '\n';                                      \
+    libMesh::Threads::lock_singleton_spin_mutex();                      \
     libMesh::MacroFunctions::report_error(__FILE__, __LINE__, LIBMESH_DATE, LIBMESH_TIME, message_stream); \
+    libMesh::Threads::unlock_singleton_spin_mutex();                    \
     LIBMESH_THROW(libMesh::FileError(filename, message_stream.str()));  \
   } while (0)