[llvm] [SimplifyCFG] Delete the unnecessary range check for small mask operation (PR #65835)

[Nikita Popov via llvm-commits]

nikic wrote:

It looks like this causes assertion failures on some build bots, for example https://lab.llvm.org/buildbot/#/builders/176/builds/6529:

> clang++: ../llvm/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:6121: (anonymous namespace)::SwitchLookupTable::SwitchLookupTable(Module &, uint64_t, ConstantInt *, const SmallVectorImpl<std::pair<ConstantInt *, Constant *>> &, Constant *, const DataLayout &, const StringRef &): Assertion `DefaultValue && "Need a default value to fill the lookup table holes."' failed.

https://github.com/llvm/llvm-project/pull/65835