[clang] Add clang atomic control options and attribute (PR #114841)

[Aaron Ballman via cfe-commits]

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@@ -623,6 +623,10 @@ class LangOptions : public LangOptionsBase {
   // WebAssembly target.
   bool NoWasmOpt = false;
 
+  /// The default atomic codegen options specified by command line in the
+  /// format of key:{on|off}.
+  std::vector<std::string> AtomicOptionsAsWritten;
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AaronBallman wrote:

If these are key/value pairs, wouldn't it make more sense to store in a set as opposed to making the consumer of language options deal with parsing?

https://github.com/llvm/llvm-project/pull/114841