[clang] macCatalyst: add SDKSettings.json as a dependency file if its potentially needed by the compiler (PR #178077)

[Ian Anderson via cfe-commits]

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@@ -3289,6 +3289,18 @@ void Darwin::addClangTargetOptions(
 
   addClangCC1ASTargetOptions(DriverArgs, CC1Args);
 
+  if (SDKInfo) {
+    // Make the SDKSettings.json an explicit dependency for the compiler
+    // invocation, in case the compiler needs to read it to remap macCatalyst
+    // versions.
+    if ((isTargetMacCatalyst() || TargetVariantTriple) &&
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ian-twilightcoder wrote:

Steven showed me lit's `%if feature` thing. That should make the tests fixable I think, giving that a try.

https://github.com/llvm/llvm-project/pull/178077