[liftoff] Ignore num locals in total frame slot count

Whenever we spill, num_used_spill_bytes_ is already updated using
RecordSpillSpillSlot, so we don't need to add the number of locals.

Bug: v8:9909
Change-Id: Ieecf957e71e0711be744a3f378d8ae11b941fc5b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1947349Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65306}

src/wasm/baseline/liftoff-assembler.h

@@ -679,8 +679,7 @@ class LiftoffAssembler : public TurboAssembler {
 
   uint32_t GetTotalFrameSlotCount() const {
     // TODO(zhin): Temporary for migration from index to offset.
-    return num_locals_ +
-           ((num_used_spill_bytes_ + kStackSlotSize - 1) / kStackSlotSize);
+    return ((num_used_spill_bytes_ + kStackSlotSize - 1) / kStackSlotSize);
   }
 
   uint32_t GetTotalFrameSlotSize() const { return num_used_spill_bytes_; }