[Bug c++/90124] [9 Regression] Compilation of llvm PDBContext.cpp fails.

[dominiq at lps dot ens.fr]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90124

--- Comment #3 from Dominique d'Humieres <dominiq at lps dot ens.fr> ---
Revision r270115 (2019-04-03) compiles the test without error, r270252
(2019-04-10) generates a lot of errors.