Changes

Summary

Commit 0bfe100145634988e4a914da776b55509ba0bec0 by n.james93 [NFC] Test case refactor
	clang-tools-extra/clangd/unittests/TUSchedulerTests.cpp
Commit 7d48eff8ba172216fca3649a3c452de4c7c16c00 by nikita.ppv [PowerPC] Avoid call to undef in test (NFC) Replace call to undef with a dummy function, to avoid affecting this change by changes to call undef folding.
	llvm/test/CodeGen/PowerPC/spe.ll
Commit d042f2db5bf0a852bdbef53ab0310d363031f56f by nikita.ppv [InstSimplify] Fold call null/undef to poison Calling null or undef results in immediate undefined behavior. Return poison instead of undef in this case, similar to what we do for immediate UB due to division by zero.
	llvm/test/Transforms/InstSimplify/undef.ll
	llvm/lib/Analysis/InstructionSimplify.cpp
	llvm/test/Transforms/GVN/PRE/volatile.ll
	llvm/test/Transforms/InstSimplify/call.ll
Commit 221c3b174b15855ec941ef60a551f22ac96a254e by nikita.ppv [InstSimplify] Canonicalize non-demanded shuffle op to poison (NFCI) I don't believe this has an observable effect, because the only thing we care about here is replacing the operand with a constant so following folds can apply. This change is just to make the representation follow canonical unary shuffle form.
	llvm/lib/Analysis/InstructionSimplify.cpp