Adding 'x64' backend.

Does not compile.

src/xenia/cpu/x64/x64_jit.h

@@ -0,0 +1,54 @@
+/**
+ ******************************************************************************
+ * Xenia : Xbox 360 Emulator Research Project                                 *
+ ******************************************************************************
+ * Copyright 2013 Ben Vanik. All rights reserved.                             *
+ * Released under the BSD license - see LICENSE in the root for more details. *
+ ******************************************************************************
+ */
+
+#ifndef XENIA_CPU_X64_X64_JIT_H_
+#define XENIA_CPU_X64_X64_JIT_H_
+
+#include <xenia/core.h>
+
+#include <xenia/cpu/jit.h>
+#include <xenia/cpu/ppc.h>
+#include <xenia/cpu/sdb.h>
+#include <xenia/cpu/x64/x64_emitter.h>
+
+#include <jit/jit.h>
+
+
+namespace xe {
+namespace cpu {
+namespace x64 {
+
+
+class X64JIT : public JIT {
+public:
+  X64JIT(xe_memory_ref memory, sdb::SymbolTable* sym_table);
+  virtual ~X64JIT();
+
+  virtual int Setup();
+
+  virtual int InitModule(ExecModule* module);
+  virtual int UninitModule(ExecModule* module);
+
+  virtual int Execute(xe_ppc_state_t* ppc_state,
+                      sdb::FunctionSymbol* fn_symbol);
+
+protected:
+  int InjectGlobals();
+
+  jit_context_t         context_;
+  X64Emitter*           emitter_;
+};
+
+
+}  // namespace x64
+}  // namespace cpu
+}  // namespace xe
+
+
+#endif  // XENIA_CPU_X64_X64_JIT_H_