[clang] [llvm] [llvm][NFC] `APFloat`: Add missing semantics to enum (PR #117291)

[Matt Arsenault via llvm-commits]

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@@ -214,13 +223,41 @@ struct APFloatBase {
     // types, there are no infinity or NaN values. The format is detailed in
     // https://www.opencompute.org/documents/ocp-microscaling-formats-mx-v1-0-spec-final-pdf
     S_Float4E2M1FN,
-
+    // TODO: Documentation is missing.
     S_x87DoubleExtended,
-    S_MaxSemantics = S_x87DoubleExtended,
+    // These are legacy semantics for the fallback, inaccrurate implementation
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arsenm wrote:

Typo inaccrurate

https://github.com/llvm/llvm-project/pull/117291