complex inlined examples.

StackFrame classes don't have a "GetPC" anymore, they have "GetFrameCodeAddress()".
This is because inlined frames will have a PC value that is the same as the 
concrete frame that owns the inlined frame, yet the code locations for the
frame can be different. We also need to be able to get the real PC value for
a given frame so that variables evaluate correctly. To get the actual PC
value for a frame you can use:

    addr_t pc = frame->GetRegisterContext()->GetPC();

Some issues with the StackFrame stomping on its own symbol context were 
resolved which were causing the information to change for a frame when the
stack ID was calculated. Also the StackFrame will now correctly store the
symbol context resolve flags for any extra bits of information that were 
looked up (if you ask for a block only and you find one, you will alwasy have
the compile unit and function).

llvm-svn: 111964