Move debug_crash_here to it's own source files

sql/debug.h

@@ -0,0 +1,39 @@
+#ifndef DEBUG_INCLUDED
+#define DEBUG_INCLUDED
+
+/* Copyright (c) 2021, MariaDB Corporation
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+/**
+  @file
+
+  Declarations for debug_crash_here and other future mariadb server debug
+  functionality.
+*/
+
+/* debug_crash_here() functionallity.
+ See mysql_test/suite/atomic/create_table.test for an example of how it
+ can be used
+*/
+
+#ifndef DBUG_OFF
+void debug_crash_here(const char *keyword);
+bool debug_simulate_error(const char *keyword, uint error);
+#else
+#define debug_crash_here(A) do { } while(0)
+#define debug_simulate_error(A, B) 0
+#endif
+
+#endif /* DEBUG_INCLUDED */