[llvm] [X86] combineBROADCAST_LOAD - merge across chains (PR #128209)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

> Something wrong with memory https://lab.llvm.org/buildbot/#/builders/169/builds/8740/steps/11/logs/stdio

Thanks for handling this @vitalybuka - rather annoying that the buildbot didn't post the fail here :/

https://github.com/llvm/llvm-project/pull/128209