cmdExePath

    fn cmdExePath(self: *WindowsCommandLineCache) Allocator.Error![:0]u16 {
        if (self.cmd_exe_path == null) {
            // Remove trailing slash from system directory path; we'll re-add it below
            const system_dir = std.mem.trimEnd(u16, windows.getSystemDirectoryWtf16Le(), &.{ '/', '\\' });
            const suffix = std.unicode.utf8ToUtf16LeStringLiteral("\\cmd.exe");
            const buf = try self.allocator.allocSentinel(u16, system_dir.len + suffix.len, 0);
            errdefer comptime unreachable;
            @memcpy(buf[0..system_dir.len], system_dir);
            @memcpy(buf[system_dir.len..], suffix);
            self.cmd_exe_path = buf;
        }
        return self.cmd_exe_path.?;
    }