[llvm] [cmake] Restore exception flags in llvm-config --cxxflags (PR #176195)

[Alexis Engelke via llvm-commits]

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@@ -41,24 +59,12 @@ function(llvm_update_compile_flags name)
       message(AUTHOR_WARNING "Exception handling requires RTTI. Enabling RTTI for ${name}")
       set(LLVM_REQUIRES_RTTI ON)
     endif()
-    if(MSVC)
-      list(APPEND LLVM_COMPILE_CXXFLAGS "/EHsc")
-    endif()
+    list(APPEND LLVM_COMPILE_CXXFLAGS ${LLVM_CXXFLAGS_EH_ENABLE})
   else()
-    if(LLVM_COMPILER_IS_GCC_COMPATIBLE)
-      list(APPEND LLVM_COMPILE_CXXFLAGS "-fno-exceptions")
-      if(LLVM_ENABLE_UNWIND_TABLES)
-        list(APPEND LLVM_COMPILE_CXXFLAGS "-funwind-tables")
-      else()
-        list(APPEND LLVM_COMPILE_CXXFLAGS "-fno-unwind-tables")
-        list(APPEND LLVM_COMPILE_CXXFLAGS "-fno-asynchronous-unwind-tables")
-      endif()
-    elseif(MSVC)
+    if(MSVC)
       list(APPEND LLVM_COMPILE_DEFINITIONS _HAS_EXCEPTIONS=0)
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aengelke wrote:

Given that this is now the only use of `LLVM_COMPILE_DEFINITIONS`, just use `target_compile_definitions(${name} PRIVATE _HAS_EXCEPTIONS=0)` here?

https://github.com/llvm/llvm-project/pull/176195