lua: add upstream patch to fix 5.3.3 loop parser

Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/lua/5.3.3/0012-fix-loop-parser.patch

@@ -0,0 +1,31 @@
+Expression list with four or more expressions in a 'for' loop can crash the interpreter.
+
+Fetch from: https://www.lua.org/bugs.html#5.3.3-1
+
+Signed-off-by: Francois Perrad <francois.perrad@gadz.org>
+
+--- a/src/lparser.c
++++ b/src/lparser.c
+@@ -323,6 +323,8 @@
+       luaK_nil(fs, reg, extra);
+     }
+   }
++  if (nexps > nvars)
++    ls->fs->freereg -= nexps - nvars;  /* remove extra values */
+ }
+ 
+ 
+@@ -1160,11 +1162,8 @@
+     int nexps;
+     checknext(ls, '=');
+     nexps = explist(ls, &e);
+-    if (nexps != nvars) {
++    if (nexps != nvars)
+       adjust_assign(ls, nvars, nexps, &e);
+-      if (nexps > nvars)
+-        ls->fs->freereg -= nexps - nvars;  /* remove extra values */
+-    }
+     else {
+       luaK_setoneret(ls->fs, &e);  /* close last expression */
+       luaK_storevar(ls->fs, &lh->v, &e);
+--