filesystem: use std for DeleteFile

Remove custom platform implementation of `DeleteFile` and replace single
use with `std::filesystem::remove` after a negative
`std::filesystem::is_directory` check.

src/xenia/base/filesystem.h

@@ -59,10 +59,6 @@ int64_t Tell(FILE* file);
 // undefined.
 bool TruncateStdioFile(FILE* file, uint64_t length);
 
-// Deletes the file at the given path.
-// Returns true if the file was found and removed.
-bool DeleteFile(const std::filesystem::path& path);
-
 struct FileAccess {
   // Implies kFileReadData.
   static const uint32_t kGenericRead = 0x80000000;

src/xenia/base/filesystem_posix.cc

@@ -131,11 +131,6 @@ bool CreateFile(const std::filesystem::path& path) {
   return false;
 }
 
-bool DeleteFile(const std::filesystem::path& path) {
-  // TODO: proper implementation.
-  return (path.c_str()) == 0 ? true : false;
-}
-
 class PosixFileHandle : public FileHandle {
  public:
   PosixFileHandle(std::filesystem::path path, int handle)

src/xenia/base/filesystem_win.cc

@@ -13,7 +13,6 @@
 #include <string>
 
 #undef CreateFile
-#undef DeleteFile
 
 #include "xenia/base/filesystem.h"
 #include "xenia/base/logging.h"
@@ -104,10 +103,6 @@ bool TruncateStdioFile(FILE* file, uint64_t length) {
   return true;
 }
 
-bool DeleteFile(const std::filesystem::path& path) {
-  return DeleteFileW(path.c_str()) ? true : false;
-}
-
 class Win32FileHandle : public FileHandle {
  public:
   Win32FileHandle(const std::filesystem::path& path, HANDLE handle)

src/xenia/vfs/devices/host_path_entry.cc

@@ -102,7 +102,8 @@ bool HostPathEntry::DeleteEntryInternal(Entry* entry) {
     return std::filesystem::remove_all(full_path);
   } else {
     // Delete file.
-    return xe::filesystem::DeleteFile(full_path);
+    return !std::filesystem::is_directory(full_path) &&
+           std::filesystem::remove(full_path);
   }
 }