[Bug libstdc++/83077] sso-string @ gnu-versioned-namespace.

[François Dumont]

Hi

     I took in bugzilla and started working on this enhancement.

     I am in the step of implementing what is in 
src/c++11/cow-stdexception.cc for the sso string. As I do not know much 
about transactionnal memory yet I prefer to ask confirmation first that 
it is indeed a necessary step to complete PR 83077 ?

Thanks,

François