RISC-V LLVM sync-up call 27th May 2021

For background on these calls, see

Reminder: the purpose is to coordinate between active contributors.
If you have support questions etc then it's best to post to llvm-dev.

We have a call every alternate Thursday at 4pm BST, via
<https://meet.google.com/ske-zcog-spp&gt;\. If you have topics to discuss,
please email me ahead and I can add them to the agenda.

We have a shared calendar that may help in keeping track, which is
accessible at:
* <https://calendar.google.com/calendar/b/1?cid=bG93cmlzYy5vcmdfMG41cGtlc2ZqY25wMGJoNWhwczFwMGJkODBAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ&gt;
* <https://calendar.google.com/calendar/ical/lowrisc.org_0n5pkesfjcnp0bh5hps1p0bd80%40group.calendar.google.com/public/basic.ics&gt;

* Explicitly emitting relaxation .option directives
* Confirming the choice of Zmmul over -mno-div
* RFC: Relaxing ISA string ordering requirements
* Final call for ELF attributes psABI changes
* PoC: Implementation of riscv_vector.h using a pragma
* Lowering split float arguments <Login;
* Builtin function naming <https://github.com/riscv/riscv-c-api-doc/issues/19&gt;
* msave-restore with tailcall patches
<Login; <Login;