Improve last commit.

(cherry picked from commit 113a168)

The `noconflict()` function checks if there's no conflicting instruction
between the current instruction and the given `ref` instruction. Also,
it avoids fusing loads if there are multiple references of the given
`ref`. The last check is performed in the presence of the `noload`
parameter. Since the `noconflict()`, which is added in the previous
patch, checks conflicts for the same `ref` as the call before, there is
no need to perform these checks again, so the corresponding parameter is
adjusted.

Sergey Kaplun:
* added the description for the problem

Part of tarantool/tarantool#10709

Reviewed-by: Sergey Bronnikov <[email protected]>
Signed-off-by: Sergey Kaplun <[email protected]>
(cherry picked from commit 18a09ad)

Author: Mike Pall

src/lj_asm_x86.h

@@ -465,7 +465,7 @@ static Reg asm_fuseload(ASMState *as, IRRef ref, RegSet allow)
       }
     } else if (ir->o == IR_ALOAD || ir->o == IR_HLOAD || ir->o == IR_ULOAD) {
       if (noconflict(as, ref, ir->o + IRDELTA_L2S, 0) &&
-	  noconflict(as, ref, IR_CALLS, 0) &&  /* Don't cross table.clear. */
+	  noconflict(as, ref, IR_CALLS, 1) &&  /* Don't cross table.clear. */
 	  !(LJ_GC64 && irt_isaddr(ir->t))) {
 	asm_fuseahuref(as, ir->op1, xallow);
 	return RID_MRM;