[llvm] [NVPTX] Rewrite sm_110* to sm_101* as demanded by PTX version (PR #218968)

[Alex MacLean via llvm-commits]

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@@ -45,6 +45,11 @@ void NVPTXSubtarget::anchor() {}
 // Note: LLVM's minimum supported PTX version is 3.2 (see FeaturePTX in
 // NVPTX.td), so older SMs that supported earlier PTX versions instead use 3.2
 // as their effective minimum.
+//
+// Note: the sm_110 architectures are older than the table's PTX 9.0 row
+// suggests, because 9.0 is where they were renamed rather than introduced. They
+// take the minimum of the sm_101 names they were renamed from; see
+// getTargetName below.
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AlexMaclean wrote:

We're describing the PTX table linked above here, not the switch below. I think this comment helps explain why they do not perfectly match. 

https://github.com/llvm/llvm-project/pull/218968