[PATCH] Fix libstdc++/6503

[Gabriel Dos Reis]

"B. Kosnik" <bkoz@nabi.net> writes:

| > I have fixed this PR according to Scott Meyers' guideline about 
| > comparison operators as non-member functions (Effective STL, 119): now
| 
| Great!
| 
| > Ok for trunk and branch?
| 
| I think so: this just adds the operators, but they are not instantiated
| in the libstdc++.so binary, are they? Thanks for the new test file!

Just curious: Isn't turning a member function into a non-member
function an ABI change?

-- Gaby