Reorganize lightuserdata interning code.

(cherry picked from commit 836fb5b)

This patch only contains a code movement of lightuserdata interning to
<lj_udata.c> file and does nothing else. This patch is backported to
simplify syncing with the upstream.

Sergey Kaplun:
* added the description for the patch

Part of tarantool/tarantool#6548
Needed for tarantool/tarantool#2712

Reviewed-by: Sergey Ostanevich <sergos@tarantool.org>
Reviewed-by: Igor Munkin <imun@tarantool.org>
Signed-off-by: Igor Munkin <imun@tarantool.org>
(cherry picked from commit 2754da4)

src/lj_api.c

@@ -716,36 +716,10 @@ LUA_API void lua_pushboolean(lua_State *L, int b)
   incr_top(L);
 }
 
-#if LJ_64
-static void *lightud_intern(lua_State *L, void *p)
-{
-  global_State *g = G(L);
-  uint64_t u = (uint64_t)p;
-  uint32_t up = lightudup(u);
-  uint32_t *segmap = mref(g->gc.lightudseg, uint32_t);
-  MSize segnum = g->gc.lightudnum;
-  if (segmap) {
-    MSize seg;
-    for (seg = 0; seg <= segnum; seg++)
-      if (segmap[seg] == up)  /* Fast path. */
-	return (void *)(((uint64_t)seg << LJ_LIGHTUD_BITS_LO) | lightudlo(u));
-    segnum++;
-  }
-  if (!((segnum-1) & segnum) && segnum != 1) {
-    if (segnum >= (1 << LJ_LIGHTUD_BITS_SEG)) lj_err_msg(L, LJ_ERR_BADLU);
-    lj_mem_reallocvec(L, segmap, segnum, segnum ? 2*segnum : 2u, uint32_t);
-    setmref(g->gc.lightudseg, segmap);
-  }
-  g->gc.lightudnum = segnum;
-  segmap[segnum] = up;
-  return (void *)(((uint64_t)segnum << LJ_LIGHTUD_BITS_LO) | lightudlo(u));
-}
-#endif
-
 LUA_API void lua_pushlightuserdata(lua_State *L, void *p)
 {
 #if LJ_64
-  p = lightud_intern(L, p);
+  p = lj_lightud_intern(L, p);
 #endif
   setrawlightudV(L->top, p);
   incr_top(L);
@@ -1199,7 +1173,7 @@ static TValue *cpcall(lua_State *L, lua_CFunction func, void *ud)
   setfuncV(L, top++, fn);
   if (LJ_FR2) setnilV(top++);
 #if LJ_64
-  ud = lightud_intern(L, ud);
+  ud = lj_lightud_intern(L, ud);
 #endif
   setrawlightudV(top++, ud);
   cframe_nres(L->cframe) = 1+0;  /* Zero results. */

src/lj_udata.c

@@ -8,6 +8,7 @@
 
 #include "lj_obj.h"
 #include "lj_gc.h"
+#include "lj_err.h"
 #include "lj_udata.h"
 
 GCudata *lj_udata_new(lua_State *L, MSize sz, GCtab *env)
@@ -34,3 +35,29 @@ void LJ_FASTCALL lj_udata_free(global_State *g, GCudata *ud)
   lj_mem_free(g, ud, sizeudata(ud));
 }
 
+#if LJ_64
+void *lj_lightud_intern(lua_State *L, void *p)
+{
+  global_State *g = G(L);
+  uint64_t u = (uint64_t)p;
+  uint32_t up = lightudup(u);
+  uint32_t *segmap = mref(g->gc.lightudseg, uint32_t);
+  MSize segnum = g->gc.lightudnum;
+  if (segmap) {
+    MSize seg;
+    for (seg = 0; seg <= segnum; seg++)
+      if (segmap[seg] == up)  /* Fast path. */
+	return (void *)(((uint64_t)seg << LJ_LIGHTUD_BITS_LO) | lightudlo(u));
+    segnum++;
+  }
+  if (!((segnum-1) & segnum) && segnum != 1) {
+    if (segnum >= (1 << LJ_LIGHTUD_BITS_SEG)) lj_err_msg(L, LJ_ERR_BADLU);
+    lj_mem_reallocvec(L, segmap, segnum, segnum ? 2*segnum : 2u, uint32_t);
+    setmref(g->gc.lightudseg, segmap);
+  }
+  g->gc.lightudnum = segnum;
+  segmap[segnum] = up;
+  return (void *)(((uint64_t)segnum << LJ_LIGHTUD_BITS_LO) | lightudlo(u));
+}
+#endif
+

src/lj_udata.h

@@ -10,5 +10,8 @@
 
 LJ_FUNC GCudata *lj_udata_new(lua_State *L, MSize sz, GCtab *env);
 LJ_FUNC void LJ_FASTCALL lj_udata_free(global_State *g, GCudata *ud);
+#if LJ_64
+LJ_FUNC void * LJ_FASTCALL lj_lightud_intern(lua_State *L, void *p);
+#endif
 
 #endif