[llvm] [RISCV] Implement RISCVInstrInfo::isAddImmediate (PR #72356)

[Craig Topper via llvm-commits]

topperc wrote:

> This appears to be breaking sanitizers: https://lab.llvm.org/buildbot/#/builders/168/builds/16852 https://lab.llvm.org/buildbot/#/builders/5/builds/38376

Since Alex it's late for Alex, I'm working on a patch.

https://github.com/llvm/llvm-project/pull/72356