FileSystem: Fix GetProgramPath() sometimes returning stale paths

See https://social.msdn.microsoft.com/Forums/windowshardware/en-US/4b7b3884-d0bb-4812-bc18-2078c61d4b90/queryfullprocessimagename-gives-wrong-path-for-renamed-directory?forum=windowsgeneraldevelopmentissues

src/common/file_system.cpp

@@ -1114,16 +1114,18 @@ bool FileSystem::DeleteDirectory(const char* Path, bool Recursive)
 
 std::string GetProgramPath()
 {
-  const HANDLE hProcess = GetCurrentProcess();
-
   std::wstring buffer;
   buffer.resize(MAX_PATH);
 
+  // Fall back to the main module if this fails.
+  HMODULE module = nullptr;
+  GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+                     reinterpret_cast<LPCWSTR>(&GetProgramPath), &module);
+
   for (;;)
   {
-    DWORD nChars = static_cast<DWORD>(buffer.size());
+    DWORD nChars = GetModuleFileNameW(module, buffer.data(), static_cast<DWORD>(buffer.size()));
-    if (!QueryFullProcessImageNameW(GetCurrentProcess(), 0, buffer.data(), &nChars) &&
+    if (nChars == static_cast<DWORD>(buffer.size()) && GetLastError() == ERROR_INSUFFICIENT_BUFFER)
-        GetLastError() == ERROR_INSUFFICIENT_BUFFER)
     {
       buffer.resize(buffer.size() * 2);
       continue;