[llvm] [RISCV][GISEL] Legalize G_INSERT_SUBVECTOR (PR #108859)

[Michael Maitland via llvm-commits]

michaelmaitland wrote:

Thanks @tschuett, I forgot to commit the changes you mention. And thanks also for updating the title. I have to post my patch for legalize extract subvector, because this patch depends on that one.

https://github.com/llvm/llvm-project/pull/108859