[clang] [clang][driver][darwin] Prefer DarwinSDKInfo for platform identification and compatibility over the -isysroot path (PR #176541)

[Cyndy Ishida via cfe-commits]

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@@ -185,6 +185,12 @@ DarwinSDKInfo::parseDarwinSDKSettingsJSON(const llvm::json::Object *Obj) {
   if (!MaximumDeploymentVersion)
     return std::nullopt;
   PlatformInfoStorageType PlatformInfos = parsePlatformInfos(*Obj, *Version);
+  auto DisplayName = Obj->getString("DisplayName");
+  if (!DisplayName) {
+    // DisplayName should always be present, but most of the testing SDKSettings
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cyndyishida wrote:

Is there a reason why the tests wouldn't be fixed? I don't think it makes sense to add logic purely for pre-dated tests.

https://github.com/llvm/llvm-project/pull/176541