[Bug target/106531] -march=rv32iabmc should also enable zba, zbb, zbc, zbs

[andrew at sifive dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106531

--- Comment #5 from Andrew Waterman <andrew at sifive dot com> ---
Yeah, RISC-V International decided to define B = {Zba, Zbb, Zbs}: note, not
Zbc.