Add NULL to the end of the match arrays

For whatever reason, making linenoise a library made most commands
matches go out of bounds causing laco to crash. By adding these NULLs
explicitly, this will insure -- hopefully -- that this wont happen.

Author: sourrust

src/commands.c

@@ -7,11 +7,11 @@
 #include "util.h"
 #include "commands/debugger.h"
 
-static const char* quit_matches[] = {"quit", "q"};
-static const char* help_matches[] = {"help", "?"};
+static const char* quit_matches[] = {"quit", "q", NULL};
+static const char* help_matches[] = {"help", "?", NULL};
 
 /* Debugger commands */
-static const char* debug_info_matches[] = {"info"};
+static const char* debug_info_matches[] = {"info", NULL};
 
 static void print_commands_help() {
   puts("  Commands available:\n");

src/flags.c

@@ -10,8 +10,8 @@ enum LacoFlags {
   LACO_VERSION
 };
 
-static const char* version_matches[] = {"-v", "--version"};
-static const char* help_matches[]    = {"-h", "-?", "--help"};
+static const char* version_matches[] = {"-v", "--version", NULL};
+static const char* help_matches[]    = {"-h", "-?", "--help", NULL};
 
 /* Check if the command flag is for version */
 static inline bool is_version(const char* arg) {