[llvm] [RISCV] Lower BUILD_VECTOR with i64 type to VID on RV32 if possible (PR #132339)

[Jim Lin via llvm-commits]

tclin914 wrote:

> > So try to customized lower it to VID before type legalization.
> 
> This is "during" type legalization, not "before".

Thanks.

https://github.com/llvm/llvm-project/pull/132339