clean up a few warnings with gcc 9.3.0

src/Makefile

@@ -9,7 +9,7 @@ PLAT= none
 
 CC= gcc
 CFLAGS= -O2 -Wall $(MYCFLAGS)
-AR= ar rcu
+AR= ar rc
 RANLIB= ranlib
 RM= rm -f
 LIBS= -lm $(MYLIBS)

src/lauxlib.c

@@ -574,7 +574,7 @@ LUALIB_API int luaL_loadfile (lua_State *L, const char *filename) {
     lf.f = freopen(filename, "rb", lf.f);  /* reopen in binary mode */
     if (lf.f == NULL) return errfile(L, "reopen", fnameindex);
     /* skip eventual `#!...' */
-   while ((c = getc(lf.f)) != EOF && c != LUA_SIGNATURE[0]) ;
+    while ((c = getc(lf.f)) != EOF && c != LUA_SIGNATURE[0]) ;
     lf.extraline = 0;
   }
   ungetc(c, lf.f);

src/ltablib.c

@@ -137,7 +137,7 @@ static void addfield (lua_State *L, luaL_Buffer *b, int i) {
   if (!lua_isstring(L, -1))
     luaL_error(L, "invalid value (%s) at index %d in table for "
                   LUA_QL("concat"), luaL_typename(L, -1), i);
-    luaL_addvalue(b);
+  luaL_addvalue(b);
 }