[cctest][arm64] Fix debug disassembler test with no simulator.

This test would fail when running natively on arm64. If USE_SIMULATOR isn't
defined, then the assembler always generates a brk instruction, regarless of the
`enable_simulator_code` Assembler option.

Change-Id: Id56788ba60ab4a13857825ebf09bf55375250c9d
Reviewed-on: https://chromium-review.googlesource.com/1174712Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#55148}

src/arm64/assembler-arm64.cc

@@ -4098,6 +4098,10 @@ void Assembler::debug(const char* message, uint32_t code, Instr params) {
     return;
   }
   // Fall through if Serializer is enabled.
+#else
+  // Make sure we haven't dynamically enabled simulator code when there is no
+  // simulator built in.
+  DCHECK(!options().enable_simulator_code);
 #endif
 
   if (params & BREAK) {

test/cctest/test-disasm-arm64.cc

@@ -1882,7 +1882,11 @@ TEST_(debug) {
     byte* buf = static_cast<byte*>(malloc(INSTR_SIZE));
     uint32_t encoding = 0;
     AssemblerOptions options;
+#ifdef USE_SIMULATOR
     options.enable_simulator_code = (i == 1);
+#else
+    CHECK(!options.enable_simulator_code);
+#endif
     Assembler* assm = new Assembler(options, buf, INSTR_SIZE);
     Decoder<DispatchingDecoderVisitor>* decoder =
         new Decoder<DispatchingDecoderVisitor>();