bloat.py syms doesn't deal well with duplicated symbols in anonymous namespaces

[froydnj]

I ran into this error today:

Traceback (most recent call last):
  File "./bloat.py", line 408, in <module>
    dump_nm(nmfile, strip_prefix=opts.strip_prefix, cppfilt=opts.cppfilt)
  File "./bloat.py", line 305, in dump_nm
    json.dumps(jsonify_tree(dirs, '[everything]'), indent=2))
  File "./bloat.py", line 270, in jsonify_tree
    subtree = jsonify_tree(val, key)
  File "./bloat.py", line 276, in jsonify_tree
    assert len(symbols) == 1, symbols.values()[0] == 1
AssertionError: True

As best I can tell, this is caused by having the following in nm.out:

0000000003de3c00 0000000000000080 d (anonymous namespace)::gHistograms
...
00000000031cf640 000000000000bf20 r (anonymous namespace)::gHistograms

which is legal C++, but problematic for any scheme that assumes that the name equivalency of symbols implies equivalency of the symbols themselves.