Added support for finding and global variables in the SBTarget and SBModule

level in the public API. 

Also modified the ValueObject values to be able to display global variables
without having a valid running process. The globals will read themselves from
the object file section data if there is no process, and from the process if
there is one.

Also fixed an issue where modifications for dynamic types could cause child
values of ValueObjects to not show up if the value was unable to evaluate
itself (children of NULL pointer objects).

llvm-svn: 134102