Add Sifive Xsfvqmacc extension intrinsics#5

yulong18 wants to merge 4 commits intosifive-rvv-intrinsicsifive/riscv-gcc:sifive-rvv-intrinsicfrom

sifive-rvv-intrinsic-tempsifive/riscv-gcc:sifive-rvv-intrinsic-tempCopy head branch name to clipboard