Merge patch series "tools: Add barrier implementations for riscv"

Charlie Jenkins <charlie@rivosinc.com> says:

Add support for riscv specific barrier implementations to the tools
tree, so that fence instructions can be emitted for synchronization.

* b4-shazam-merge:
  tools: Optimize ring buffer for riscv
  tools: Add riscv barrier implementation

Link: https://lore.kernel.org/r/20240806-optimize_ring_buffer_read_riscv-v2-0-ca7e193ae198@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>