[llvm] [IR] Remove support for lshr/ashr constant expressions (PR #71955)

[Nicolai Hähnle via llvm-commits]

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@@ -3948,7 +3945,6 @@ bool LLParser::parseValID(ValID &ID, PerFunctionState *PFS, Type *ExpectedTy) {
     unsigned Flags = 0;
     if (NUW)   Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
     if (NSW)   Flags |= OverflowingBinaryOperator::NoSignedWrap;
-    if (Exact) Flags |= PossiblyExactOperator::IsExact;
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nhaehnle wrote:

Unrelated musing: I've been wondering for a long time if we couldn't turn `or` and `and` into possibly exact operators with the meaning of `exact` being "the set / unset bits of the operands are disjoint". The idea being that this might help sometimes with issues caused by LLVM eagerly replacing `add` with `or` in address expressions.

https://github.com/llvm/llvm-project/pull/71955