[llvm] Make RAUW skip instances where operand is the replacement node (PR #212724)

[Matt Arsenault via llvm-commits]

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@@ -0,0 +1,18 @@
+; RUN: llc < %s -mtriple=x86_64 -mattr=+avx2 -o /dev/null
+;
+; Verify that CSE-reusing a TokenFactor during broadcast-load combining does not
+; introduce a self-reference while replacing the old chain.
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
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arsenm wrote:

The triple on the command line is redundant with the triple in the file, choose one or the other. same goes for target-features / matte 

https://github.com/llvm/llvm-project/pull/212724