[llvm] [IR] Add nowrap flags for trunc instruction (PR #85592)

[Yingwei Zheng via llvm-commits]

dtcxzyw wrote:

> ********************
Failed Tests (8):
  LLVM :: CodeGen/Hexagon/packed-store.ll
  LLVM :: Transforms/GVN/callbr-scalarpre-critedge.ll
  LLVM :: Transforms/GVN/invariant.group.ll
  LLVM :: Transforms/GVN/pre-new-inst.ll
  LLVM :: Transforms/GVNHoist/hoist-pr20242.ll
  LLVM :: Transforms/GVNSink/sink-common-code.ll
  LLVM :: Transforms/PhaseOrdering/X86/vec-load-combine.ll
  LLVM :: Transforms/SimplifyCFG/dont-hoist-deoptimize.ll

https://github.com/llvm/llvm-project/pull/85592