Guard `Run` for platforms we're not compiling to, yet.

Change-Id: I0dc210d2734e95714bed6c481a31fa4daabb9332
diff --git a/compiler/optimizing/codegen_test.cc b/compiler/optimizing/codegen_test.cc
index 3b91ca1..c3baf1a 100644
--- a/compiler/optimizing/codegen_test.cc
+++ b/compiler/optimizing/codegen_test.cc
@@ -47,6 +47,7 @@
   DISALLOW_COPY_AND_ASSIGN(InternalCodeAllocator);
 };
 
+#if defined(__i386__) || defined(__arm__) || defined(__x86_64__)
 static void Run(const InternalCodeAllocator& allocator, bool has_result, int32_t expected) {
   typedef int32_t (*fptr)();
   CommonCompilerTest::MakeExecutable(allocator.GetMemory(), allocator.GetSize());
@@ -55,6 +56,7 @@
     CHECK_EQ(result, expected);
   }
 }
+#endif
 
 static void TestCode(const uint16_t* data, bool has_result = false, int32_t expected = 0) {
   ArenaPool pool;