bonnie++: update to 2.00a

Add custom meson build since the Makefile requires too much patching
anyway.

Stop using uClibc++. It will be removed in the near future.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

utils/bonnie++/patches/102-add-missing-cast.patch

@@ -0,0 +1,23 @@
+From 2e3e25454a165d55cbcd4fc78539454d4e0d8d51 Mon Sep 17 00:00:00 2001
+From: Rosen Penev <rosenp@gmail.com>
+Date: Mon, 22 Feb 2021 16:07:02 -0800
+Subject: [PATCH] add missing cast
+
+Fixes -Wformat
+
+Signed-off-by: Rosen Penev <rosenp@gmail.com>
+---
+ bon_time.cpp | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/bon_time.cpp
++++ b/bon_time.cpp
+@@ -146,7 +146,7 @@ int BonTimer::print_stat(tests_t test, i
+         }
+         else
+         {
+-          fprintf(m_fp, " %5d", stat);
++          fprintf(m_fp, " %5d", int(stat));
+         }
+       }
+       else