Added some casts for 32-bit machines

When both 'int' and 'l_obj' have 32 bits, an unsigned int needs a
cast to be assigned to 'l_obj'. (As long as 'l_obj' can count the
total memory used by the system, these casts should be safe.)

lgc.c

@@ -624,7 +624,7 @@ static l_mem traversetable (global_State *g, Table *h) {
         linkgclist(h, g->allweak);  /* must clear collected entries */
       break;
   }
-  return 1 + 2*sizenode(h) + h->asize;
+  return cast(l_mem, 1 + 2*sizenode(h) + h->asize);
 }
 
 

llimits.h

@@ -20,8 +20,8 @@
 /*
 ** 'l_mem' is a signed integer big enough to count the total memory
 ** used by Lua.  (It is signed due to the use of debt in several
-** computations.)  Usually, 'ptrdiff_t' should work, but we use 'long'
-** for 16-bit machines.
+** computations.) 'lu_mem' is a corresponding unsigned type.  Usually,
+** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines.
 */
 #if defined(LUAI_MEM)		/* { external definitions? */
 typedef LUAI_MEM l_mem;

lobject.c

@@ -87,7 +87,7 @@ lu_byte luaO_codeparam (unsigned int p) {
 ** overflow, so we check which order is best.
 */
 l_mem luaO_applyparam (lu_byte p, l_mem x) {
-  unsigned int m = p & 0xF;  /* mantissa */
+  int m = p & 0xF;  /* mantissa */
   int e = (p >> 4);  /* exponent */
   if (e > 0) {  /* normalized? */
     e--;  /* correct exponent */