drsyms add scope info

_From [bruen...@google.com](https://code.google.com/u/109494838902877177630/) on May 06, 2011 11:52:54_

my original drsyms design focused on my initial use case in Dr. Memory and went with a simple interface:
- Have a simple platform-independent symbol table format that ignores
scopes and other complexities (unless you have a use case that requires
scopes?)
- The client symbol query API is also very simple (unless we have use cases
that need more):
- look up symbol name from address
- look up address from symbol name
- look up func+file+line# from address

The client query API is abstracted away from the underlying symbol table
format, which is not exposed, so that we can change the format later and
add scopes, etc. if we need them.

this issue covers adding more complex symbol info such as scopes

_Original issue: http://code.google.com/p/dynamorio/issues/detail?id=447_