<rdar://problem/11275622>

Added new API to lldb::SBTypeMember for bitfields:

    bool SBTypeMember::IsBitfield();
    uint32_t SBTypeMember::GetBitfieldSizeInBits();

Also added new properties for easy access. Now SBTypeMember objects in python have a "fields" property for all type fields, "bases" for all direct bases, "vbases" for all virtual base classes and "members" for a combo of all three organized by bit offset. They all return a python list() of SBTypeMember objects. Usage:
(lldb) script
>>> t = lldb.target.FindFirstType("my_type")
>>> for field in t.fields:
...     print field
>>> for vbase in t.vbases:
...     print vbase
>>> for base in t.bases:
...     print base
>>> for member in t.members:
...     print member

Also added new "is_bitfield" property to the SBTypeMember objects that will return the result of SBTypeMember::IsBitfield(), and "bitfield_bit_size" which will return the result of SBTypeMember::GetBitfieldSizeInBits();

I also fixed "SBTypeMember::GetOffsetInBytes()" to return the correct byte offset.

llvm-svn: 161091