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/gpu/dxbc_shader_translator.cc

@@ -1618,7 +1618,7 @@ void DxbcShaderTranslator::EmitInstructionDisassembly() {
     return;
   }
 
-  const char* source = instruction_disassembly_buffer_.GetString();
+  const char* source = instruction_disassembly_buffer_.buffer();
   uint32_t length = uint32_t(instruction_disassembly_buffer_.length());
   // Trim leading spaces and trailing new line.
   while (length != 0 && source[0] == ' ') {