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/testing/premake5.lua

@@ -7,12 +7,13 @@ project("xenia-cpu-ppc-tests")
   kind("ConsoleApp")
   language("C++")
   links({
+    "capstone", -- cpu-backend-x64
+    "fmt",
+    "mspack",
     "xenia-core",
     "xenia-cpu-backend-x64",
     "xenia-cpu",
     "xenia-base",
-    "capstone", -- cpu-backend-x64
-    "mspack",
   })
   files({
     "ppc_testing_main.cc",
@@ -40,6 +41,7 @@ project("xenia-cpu-ppc-nativetests")
   kind("ConsoleApp")
   language("C++")
   links({
+    "fmt",
     "xenia-base",
   })
   files({