Enable SELECT query planning tracing when compiled with

SQLITE_ENABLE_SELECTTRACE and either SQLITE_DEBUG or SQLITE_TEST.

FossilOrigin-Name: cbe0cf9ddf46f0a678c85d49bfa74e3b7712e1a1

src/shell.c

@@ -3101,6 +3101,15 @@ static int do_meta_command(char *zLine, ShellState *p){
     }
   }else
 
+
+#if defined(SQLITE_DEBUG) && defined(SQLITE_ENABLE_SELECTTRACE)
+  if( c=='s' && n==11 && strncmp(azArg[0], "selecttrace", n)==0 ){
+    extern int sqlite3SelectTrace;
+    sqlite3SelectTrace = nArg>=2 ? booleanValue(azArg[1]) : 0xff;
+  }else
+#endif
+
+
 #ifdef SQLITE_DEBUG
   /* Undocumented commands for internal testing.  Subject to change
   ** without notice. */