When libSystem's initializers are run, they call back into dyld's registerThreadHelpers which creates a pthread key and calls __Unwind_SjLj_SetThreadK

returns true if prebinding was used in main executable

Implementation that works with existing dyld data structures

<rdar://problem/10583252> Add dyld to uuidArray to enable symbolication of stackshots

In order for register_func_for_add_image() callbacks to to be called bottom up, we need to maintain a list of root images. The main executable is usal

Try to apply an augmenting list */

this is called by initializeMainExecutable() to interpose on the initial set of images

------------------------------------------------------------------------------- augment(): Add item to the mapping. Construct a spanning tree of *b*s

This bar is a "resolver" function that return the actual address of "bar"