[llvm] [AArch64][GlobalISel] Add lowering for constant BIT/BIF/BSP (PR #65897)

[Amara Emerson via llvm-commits]

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@@ -216,7 +216,7 @@ def G_PREFETCH : AArch64GenericInstruction {
 }
 
 // Generic bitwise insert if true.
-def G_BIT : AArch64GenericInstruction {
+def G_BSP : AArch64GenericInstruction {
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aemerson wrote:

And this opcode needs a bit of documentation since it's not a real AArch64 instruction.

https://github.com/llvm/llvm-project/pull/65897