[llvm] [GlobalISel] Support fixed vectors in constant-fold combines. (PR #220876)

[Matt Arsenault via llvm-commits]

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@@ -408,3 +408,111 @@ body:             |
     RET_ReallyLR implicit $s0
 
 ...
+---
+name:            add_vector
+legalized:       true
+liveins:
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arsenm wrote:

Don't need this 

https://github.com/llvm/llvm-project/pull/220876