[clang] [RISCV] Allow -mcmodel= to accept large for RV64 (PR #107817)

[Pengcheng Wang via cfe-commits]

wangpc-pp wrote:

> What's the status of backend support for the large code model? That would presumably be a prerequisite to landing this.

It was just merged: https://github.com/llvm/llvm-project/pull/70308.

https://github.com/llvm/llvm-project/pull/107817