[llvm] [RISCV][TTI] Enable masked interleave access (PR #151665)

[Mel Chen via llvm-commits]

Mel-Chen wrote:

> This gives some nice improvements across llvm-test-suite, uuencode is 33% faster now and there's some other big improvements to TSVC: https://lnt.lukelau.me/db_default/v4/nts/821

Thanks to @preames for the help. :)

https://github.com/llvm/llvm-project/pull/151665