HMCLauncher: try bundled JRE

HMCLauncher/HMCL/os.h

@@ -0,0 +1,23 @@
+#pragma once
+#include <string>
+#include <windows.h>
+
+const int MAX_KEY_LENGTH = 255;
+const int MAX_VALUE_NAME = 16383;
+
+// Query registry value of class root hKey, key path subKey, stores result in parameter out.
+LSTATUS MyRegQueryValue(HKEY hKey, LPCWSTR subKey, DWORD dwType, std::wstring &out);
+
+// Get module file name, stores result in parameter out.
+LSTATUS MyGetModuleFileName(HMODULE hModule, std::wstring &out);
+
+// Get environment variable by name, C++ style, stores the value in parameter out.
+LSTATUS MyGetEnvironmentVariable(LPCWSTR name, std::wstring &out);
+
+// Create process by invoking CreateProcess, only pass command.
+bool MyCreateProcess(const std::wstring &command);
+
+// Check if file lpPath exists.
+bool FindFirstFileExists(LPCWSTR lpPath, DWORD dwFilter);
+
+bool GetArch(bool &is64Bit);