https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77728
--- Comment #59 from Jakub Jelinek <jakub at gcc dot gnu.org> --- It does mention it: "GCC has been updated to the latest revision of the procedure call standard (AAPCS64) to provide support for paramater passing when data types have been over-aligned." There were two issues, one is that old GCC had issues with passing of overaligned and underaligned variables by value. This was a problem in GCC < 5.2 for arm32 and GCC <= 6.x for aarch64. And another thing was the bug mentioned here, introduced for arm32 in 5.2 and for aarch64 only during development of GCC 7. So there was no release for aarch64 with that bug.
