C++17ification.

C++17ification!

- Filesystem interaction now uses std::filesystem::path.
- Usage of const char*, std::string have been changed to
  std::string_view where appropriate.
- Usage of printf-style functions changed to use fmt.

src/xenia/cpu/ppc/ppc_context.h

@@ -2,7 +2,7 @@
  ******************************************************************************
  * Xenia : Xbox 360 Emulator Research Project                                 *
  ******************************************************************************
- * Copyright 2013 Ben Vanik. All rights reserved.                             *
+ * Copyright 2020 Ben Vanik. All rights reserved.                             *
  * Released under the BSD license - see LICENSE in the root for more details. *
  ******************************************************************************
  */
@@ -432,7 +432,7 @@ typedef struct PPCContext_s {
 
   void SetRegFromString(const char* name, const char* value);
   bool CompareRegWithString(const char* name, const char* value,
-                            char* out_value, size_t out_value_size) const;
+                            std::string& result) const;
 } PPCContext;
 #pragma pack(pop)
 static_assert(sizeof(PPCContext) % 64 == 0, "64b padded");