iOS other linker flags

值:-objC,-all_load,-force_load

-all_load : 在iOS 中，使用-all_load时，如果静态库中有类别时会出问题，使用其他两个值则不会有问题。

-all_load: forces the linker to load all object files from every archive it sees, even those without Objective-C code.

-force_load: is available in Xcode 3.2 and later. It allows finer grain control of archive loading. Each -force_load option must be followed by a path to an archive, and every object file in that archive will be loaded.