[llvm] [LegalizeTypes][X86][PowerPC] Use shift by 1 instead of adding a value to itself to double. (PR #86857)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

And if you actually care about being undef-correct, I think you need to freeze the operand anyway: the splitting of the insert itself increases the number of uses of an undef value.

https://github.com/llvm/llvm-project/pull/86857