[no-wasm] Fix compilation by #if'ing out test code

The test was extended in this CL: https://crrev.com/c/2762420
It now uses wasm::SimdShuffle, which is only available if webassembly is
enabled.
Thus, #if out the test if webassembly is disabled.

Drive-by: Add a missing include.

R=jkummerow@chromium.org
CC=zhin@chromium.org

Bug: v8:11238
Change-Id: I1b53d0145467b58616a161944fb88d2ca256fd58
Cq-Include-Trybots: luci.v8.try:v8_linux64_no_wasm_compile_rel
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2772978Reviewed-by: Zhi An Ng <zhin@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73517}

test/unittests/compiler/x64/instruction-selector-x64-unittest.cc

@@ -9,6 +9,10 @@
 #include "src/objects/objects-inl.h"
 #include "test/unittests/compiler/backend/instruction-selector-unittest.h"
 
+#if V8_ENABLE_WEBASSEMBLY
+#include "src/wasm/simd-shuffle.h"
+#endif  // V8_ENABLE_WEBASSEMBLY
+
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ -1939,6 +1943,7 @@ TEST_F(InstructionSelectorTest, SIMDSplatZero) {
   }
 }
 
+#if V8_ENABLE_WEBASSEMBLY
 struct ArchShuffle {
   uint8_t shuffle[kSimd128Size];
   ArchOpcode arch_opcode;
@@ -2197,6 +2202,7 @@ TEST_P(InstructionSelectorSIMDArchShuffleTest, SIMDArchShuffle) {
 INSTANTIATE_TEST_SUITE_P(InstructionSelectorTest,
                          InstructionSelectorSIMDArchShuffleTest,
                          ::testing::ValuesIn(kArchShuffles));
+#endif  // V8_ENABLE_WEBASSEMBLY
 
 }  // namespace compiler
 }  // namespace internal