Created attachment 161502 [details]
v1-0001-VEX-Add-Ijk_ExitBB-IR-for-potential-critical-state-c.patch

Generally we use Ijk_Boring in most jump instructions,
and some backends use this IR to make BB optimization 'chaining' in instruction selection stage.

For some special ISAs like RISC-V vector [1], vsetvl/vsetvli instruction will set VTYPE/VL CSRs
which are depended by next BB, so we add this new Ijk_ExitBB IR to exit BB
without any optimization.

[1] https://github.com/riscv/riscv-v-spec