[llvm] [ValueTracking] Allow tracking values through Integral AddrSpaceCasts (PR #70483)

[Matt Arsenault via llvm-commits]

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@@ -148,6 +148,14 @@ struct KnownBits {
     return Max;
   }
 
+  KnownBits clearLowBits(unsigned BitWidth) {
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arsenm wrote:

I'd expect this to follow the convention of setAllOnes, mutate in place rather than return a new copy 

https://github.com/llvm/llvm-project/pull/70483