MIPS[64]: Fix wrong operand call in SIMD S8x16Concat operator

TEST=cctest/test-run-wasm-simd/RunWasm_S8x16Concat_turbofan

Change-Id: Ifcc14b57d65d15e5ae8477a05746027356bac547
Reviewed-on: https://chromium-review.googlesource.com/1166909Reviewed-by: Bill Budge <bbudge@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Ivica Bogosavljevic <ibogosavljevic@wavecomp.com>
Cr-Commit-Position: refs/heads/master@{#55012}

src/compiler/mips/instruction-selector-mips.cc

@@ -2170,8 +2170,8 @@ void InstructionSelector::VisitS8x16Shuffle(Node* node) {
   uint8_t offset;
   MipsOperandGenerator g(this);
   if (TryMatchConcat(shuffle, &offset)) {
-    Emit(kMipsS8x16Concat, g.DefineSameAsFirst(node), g.UseRegister(input0),
-         g.UseRegister(input1), g.UseImmediate(offset));
+    Emit(kMipsS8x16Concat, g.DefineSameAsFirst(node), g.UseRegister(input1),
+         g.UseRegister(input0), g.UseImmediate(offset));
     return;
   }
   if (TryMatch32x4Shuffle(shuffle, shuffle32x4)) {

src/compiler/mips64/instruction-selector-mips64.cc

@@ -2837,8 +2837,8 @@ void InstructionSelector::VisitS8x16Shuffle(Node* node) {
   uint8_t offset;
   Mips64OperandGenerator g(this);
   if (TryMatchConcat(shuffle, &offset)) {
-    Emit(kMips64S8x16Concat, g.DefineSameAsFirst(node), g.UseRegister(input0),
-         g.UseRegister(input1), g.UseImmediate(offset));
+    Emit(kMips64S8x16Concat, g.DefineSameAsFirst(node), g.UseRegister(input1),
+         g.UseRegister(input0), g.UseImmediate(offset));
     return;
   }
   if (TryMatch32x4Shuffle(shuffle, shuffle32x4)) {