Increase buffer for uncaught exception / std::terminate

Use PIPE_BUF over some magic number 1024 in terminate_handler, since
according to pipe(7):

    PIPE_BUF
           POSIX.1  says  that  write(2)s of less than PIPE_BUF bytes must be atomic

Also note that 1024, is too small, especially for C++ stacktraces (and
especially for debug builds, that contains lots of non-inlined helpers
for various ptrs).

base/daemon/BaseDaemon.cpp

@@ -416,7 +416,7 @@ static void sanitizerDeathCallback()
     else
         log_message = "Terminate called without an active exception";
 
-    static const size_t buf_size = 1024;
+    static const size_t buf_size = PIPE_BUF;
 
     if (log_message.size() > buf_size - 16)
         log_message.resize(buf_size - 16);