[wasm-simd][arm] Fix i64x2.neg

We were using vqsub incorrectly (which saturates), we need vsub
(wraparound).

Found this issue while running spec test simd_i64x2_arith.js.

Bug: v8:10835
Change-Id: Ic9d45d69e64fa5ff9ddad5de4690f3dd32d1384e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2389100Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69659}

src/compiler/backend/arm/code-generator-arm.cc

@@ -2150,7 +2150,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kArmI64x2Neg: {
       Simd128Register dst = i.OutputSimd128Register();
       __ vmov(dst, uint64_t{0});
-      __ vqsub(NeonS64, dst, dst, i.InputSimd128Register(0));
+      __ vsub(Neon64, dst, dst, i.InputSimd128Register(0));
       break;
     }
     case kArmI64x2Shl: {

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

@@ -2488,8 +2488,8 @@ void LiftoffAssembler::emit_i64x2_neg(LiftoffRegister dst,
   QwNeonRegister zero =
       dst == src ? temps.AcquireQ() : liftoff::GetSimd128Register(dst);
   vmov(zero, uint64_t{0});
-  vqsub(NeonS64, liftoff::GetSimd128Register(dst), zero,
-        liftoff::GetSimd128Register(src));
+  vsub(Neon64, liftoff::GetSimd128Register(dst), zero,
+       liftoff::GetSimd128Register(src));
 }
 
 void LiftoffAssembler::emit_i64x2_shl(LiftoffRegister dst, LiftoffRegister lhs,