Revert "[liftoff] Check fp_pair when looking up register for reuse"

This reverts commit 548fda4a.

Reason for revert: Segfault on nosse bot: https://ci.chromium.org/p/v8/builders/ci/V8%20Linux/35905?

Original change's description:
> [liftoff] Check fp_pair when looking up register for reuse
> 
> Given two registers that are both not gp_pair, one could be an fp_pair,
> and the other not, and we will incorrect call == on them. The current
> check needs to be expanded to check that both registers are fp_pair.
> 
> Bug: chromium:1054466
> Change-Id: Ib986c002a8a5cadb9668458597a797cecfd971b1
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2070006
> Commit-Queue: Zhi An Ng <zhin@chromium.org>
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#66402}

TBR=clemensb@chromium.org,zhin@chromium.org

Change-Id: I56f13406ef3cc3793c9d0e2273c4dc5fb0e3de38
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:1054466
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2069327Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66405}

src/wasm/baseline/liftoff-assembler.cc

@@ -353,9 +353,7 @@ class RegisterReuseMap {
 
   base::Optional<LiftoffRegister> Lookup(LiftoffRegister src) {
     for (auto it = map_.begin(), end = map_.end(); it != end; it += 2) {
-      if (it->is_gp_pair() == src.is_gp_pair() &&
-          it->is_fp_pair() == src.is_fp_pair() && *it == src)
-        return *(it + 1);
+      if (it->is_gp_pair() == src.is_gp_pair() && *it == src) return *(it + 1);
     }
     return {};
   }

test/mjsunit/regress/wasm/regress-1054466.js

-// Copyright 2020 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --experimental-wasm-simd
-
-load('test/mjsunit/wasm/wasm-module-builder.js');
-
-const builder = new WasmModuleBuilder();
-builder.addType(makeSig([kWasmI32, kWasmI32, kWasmI32], [kWasmI32]));
-// Generate function 1 (out of 1).
-builder.addFunction(undefined, 0 /* sig */)
-  .addLocals({i32_count: 2}).addLocals({f32_count: 2})
-  .addBodyWithEnd([
-// signature: i_iii
-// body:
-kExprI32Const, 0x00,  // i32.const
-kExprI32Const, 0x00,  // i32.const
-kExprI32Const, 0xf9, 0x00,  // i32.const
-kExprI32Ior,  // i32.or
-kExprI32Eqz,  // i32.eqz
-kExprI32Add,  // i32.Add
-kSimdPrefix, kExprI32x4Splat,  // i32x4.splat
-kExprF32Const, 0x46, 0x5d, 0x00, 0x00,  // f32.const
-kExprI32Const, 0x83, 0x01,  // i32.const
-kExprI32Const, 0x83, 0x01,  // i32.const
-kExprI32Const, 0x83, 0x01,  // i32.const
-kExprI32Add,  // i32.Add
-kExprI32Add,  // i32.Add
-kExprIf, kWasmI32,  // if @33 i32
-  kExprI32Const, 0x00,  // i32.const
-kExprElse,  // else @37
-  kExprI32Const, 0x00,  // i32.const
-  kExprEnd,  // end @40
-kExprIf, kWasmI32,  // if @41 i32
-  kExprI32Const, 0x00,  // i32.const
-kExprElse,  // else @45
-  kExprI32Const, 0x00,  // i32.const
-  kExprEnd,  // end @48
-kExprF32ReinterpretI32,  // f32.reinterpret_i32
-kExprF32Max,  // f32.max
-kSimdPrefix, kExprF32x4Splat,  // f32x4.splat
-kExprI32Const, 0x83, 0x01,  // i32.const
-kSimdPrefix, kExprI8x16Splat,  // i8x16.splat
-kSimdPrefix, kExprF64x2Add,  // f64x2.add
-kSimdPrefix, kExprI64x2Add,  // i64x2.add
-kSimdPrefix, kExprS1x8AnyTrue,  // s1x8.any_true
-kExprEnd,  // end @64
-]);
-builder.addExport('main', 0);
-const instance = builder.instantiate();
-print(instance.exports.main(1, 2, 3));

test/mjsunit/wasm/wasm-module-builder.js

@@ -469,15 +469,10 @@ let kExprI64AtomicCompareExchange32U = 0x4e;
 // Simd opcodes.
 let kExprS128LoadMem = 0x00;
 let kExprS128StoreMem = 0x01;
-let kExprI8x16Splat = 0x04;
 let kExprI32x4Splat = 0x0c;
-let kExprF32x4Splat = 0x12;
 let kExprI32x4Eq = 0x2c;
-let kExprS1x8AnyTrue = 0x63;
 let kExprS1x4AllTrue = 0x75;
-let kExprI64x2Add = 0x8a;
 let kExprF32x4Min = 0x9e;
-let kExprF64x2Add = 0xa5;
 
 // Compilation hint constants.
 let kCompilationHintStrategyDefault = 0x00;