MIPS: Fix broken build

Redefinition of GetHalfStackSlot after commit 5ea59597.

Change-Id: Ib2b1fe6bd130c6737a73ef55b09dc80f4cd9b3fb
Reviewed-on: https://chromium-review.googlesource.com/c/1396077Reviewed-by: Sreten Kovacevic <skovacevic@wavecomp.com>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Predrag Rudic <prudic@wavecomp.com>
Cr-Commit-Position: refs/heads/master@{#58543}

src/wasm/baseline/mips/liftoff-assembler-mips.h

@@ -41,12 +41,6 @@ inline MemOperand GetHalfStackSlot(uint32_t index, RegPairHalf half) {
   return MemOperand(fp, -kFirstStackSlotOffset - offset);
 }
 
-inline MemOperand GetHalfStackSlot(uint32_t index, RegPairHalf half) {
-  STATIC_ASSERT(kLowWord == 0);
-  STATIC_ASSERT(kHighWord == 1);
-  return GetHalfStackSlot(2 * index + half);
-}
-
 inline MemOperand GetInstanceOperand() { return MemOperand(fp, -8); }
 
 inline void Load(LiftoffAssembler* assm, LiftoffRegister dst, Register base,