[clang] [Driver] Add ExclusiveGroup feature to multilib.yaml. (PR #69447)

[Fangrui Song via cfe-commits]

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@@ -152,6 +180,7 @@ template <> struct llvm::yaml::MappingTraits<MultilibSerialization> {
   static void mapping(llvm::yaml::IO &io, MultilibSerialization &V) {
     io.mapRequired("Dir", V.Dir);
     io.mapRequired("Flags", V.Flags);
+    io.mapOptional("ExclusiveGroup", V.ExclusiveGroup);
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MaskRay wrote:

`ExclusiveGroup` looks good to me and I agree that `Group` could be confusing.

https://github.com/llvm/llvm-project/pull/69447