[llvm] Create a CharSetConverter class with both iconv and icu support (PR #74516)

[Eli Friedman via llvm-commits]

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@@ -257,6 +257,26 @@ else()
   set(LLVM_ENABLE_TERMINFO 0)
 endif()
 
+#Check for icu.
+if(LLVM_ENABLE_ICU)
+  find_package(ICU COMPONENTS uc i18n)
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efriedma-quic wrote:

I can't think of anything better.

This won't work on Windows.

https://github.com/llvm/llvm-project/pull/74516