array: Fix structured bindings

[ishan-karmakar]

Moves all get overloads for frg::array to frg namespace as Clang and GCC expect get to be in inner type's namespace. More info here in Case 2.

[ArsenArsen]

hmm, the get invocation should undergo ADL, though, per [dcl.struct.bind]#5, odd that it doesn't.

please add a testcase also

(unrelated, maybe we should start phasing out frg::array and other stuff overlapping with std that is available for freestanding in favor of freestanding - libstdc++ contains quite a few things in freestanding also, and I hope to add to that set this year)

[ArsenArsen]

oh, sorry, I read your patch backwards - that explains it :-)

in that case, this looks OK (but perhaps we should keep both functions for BW compatibility, and we should still add a test)

[ishan-karmakar]

I added a testcase for frg::array but I didn't add a reference test since arrays of references are illegal. I tried to add the get overloads back to the std namespace for bw compatibility, but an error is thrown since the get overload is ambiguous between frg and std namespace.

(btw, I agree that frg::array should be phased out as it is identical to std::array)

[ArsenArsen]

nice! thanks