luajit: solve blockdebug falsely triggering since its flag collided with something

Author: RaphaelIT7

LuaJIT-2.1/src/lj_cdata.c

@@ -43,7 +43,7 @@ GCcdata *lj_cdata_newv(lua_State *L, CTypeID id, CTSize sz, CTSize align)
   setgcrefr(cd->nextgc, g->gc.root);
   setgcref(g->gc.root, obj2gco(cd));
   newwhite(g, obj2gco(cd));
-  cd->marked |= 0x80;
+  cd->marked |= LJ_GC_ISCDATA;
   cd->gct = ~LJ_TCDATA;
   cd->ctypeid = id;
   return cd;

LuaJIT-2.1/src/lj_gc.h

@@ -23,8 +23,9 @@ enum {
 #define LJ_GC_CDATA_FIN	0x10
 #define LJ_GC_FIXED	0x20
 #define LJ_GC_SFIXED	0x40
+#define LJ_GC_ISCDATA   0x80
 #define LJ_GC_READONLY	0x80
-#define LJ_GC_BLOCKDEBUG  0x80 // Same as LJ_GC_READONLY, but we'll use this one for functions.
+#define LJ_GC_BLOCKDEBUG  0x08 // Same as LJ_GC_WEAKKEY but we can use it for functions
 
 #define LJ_GC_WHITES	(LJ_GC_WHITE0 | LJ_GC_WHITE1)
 #define LJ_GC_COLORS	(LJ_GC_WHITES | LJ_GC_BLACK)

LuaJIT-2.1/src/lj_obj.h

@@ -358,7 +358,7 @@ typedef struct GCcdataVar {
 } GCcdataVar;
 
 #define cdataptr(cd)	((void *)((cd)+1))
-#define cdataisv(cd)	((cd)->marked & 0x80)
+#define cdataisv(cd)	((cd)->marked & LJ_GC_ISCDATA)
 #define cdatav(cd)	((GCcdataVar *)((char *)(cd) - sizeof(GCcdataVar)))
 #define cdatavlen(cd)	check_exp(cdataisv(cd), cdatav(cd)->len)
 #define sizecdatav(cd)	(cdatavlen(cd) + cdatav(cd)->extra)