[clang] [llvm] [driver] Make --version show if assertions, etc. are enabled (PR #87585)

[Fangrui Song via cfe-commits]

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@@ -2734,6 +2734,39 @@ void cl::PrintHelpMessage(bool Hidden, bool Categorized) {
     CommonOptions->CategorizedHiddenPrinter.printHelp();
 }
 
+ArrayRef<StringRef> cl::CompilerBuildConfig = {
+#if LLVM_IS_DEBUG_BUILD
+    "+unoptimized",
+#endif
+#ifndef NDEBUG
+    "+assertions",
+#endif
+#ifdef EXPENSIVE_CHECKS
+    "+expensive-checks",
+#endif
+#if __has_feature(address_sanitizer)
+    "+asan",
+#endif
+#if __has_feature(undefined_behavior_sanitizer)
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MaskRay wrote:

sort sanitizers alphabetically?

You can add thread_sanitizer and `hwaddress_sanitizer` as well 

https://github.com/llvm/llvm-project/pull/87585