[clang] [llvm] Enable ClangIR Build By Default (PR #221291)

[Erich Keane via cfe-commits]

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@@ -190,6 +190,12 @@ if(CLANG_ENABLE_LIBXML2)
   endif()
 endif()
 
+# Standalone builds don't inherit this flag from the llvm/CMakeLists, so set it
+# here.
+if(CLANG_BUILT_STANDALONE)
+  option(CLANG_ENABLE_CIR "Build ClangIR support into the compiler" OFF)
+endif()
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erichkeane wrote:

@joker-eph did most of the work here, so he's perhaps more knowledgable here?  

I think the real limitation is no one at any point ever looked into the standalone build.  IF you could put one together, we'd be extremely appreciative!  @bcardosolopes might have some more context as well.

https://github.com/llvm/llvm-project/pull/221291