[clang] Make CIR assembly formats strict properties compatible (PR #226600)

[Henrich Lauko via cfe-commits]

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@@ -4527,7 +4540,8 @@ def CIR_LLVMIntrinsicCallOp : CIR_Op<"call_llvm_intrinsic"> {
   let skipDefaultBuilders = 1;
 
   let assemblyFormat = [{
-    $intrinsic_name $arg_ops `:` functional-type($arg_ops, $result) attr-dict
+    $intrinsic_name $arg_ops `:` functional-type($arg_ops, $result)
+    (`fastmath` `(` $fastmath_flags^ `)`)? attr-dict
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xlauko wrote:

Is this unambiguous parse as this:

```suggestion
    ($fastmath_flags^)? attr-dict
```

I kinda don't like we repeat all properties twice now in the IR. This happens now on many places. 

If you need to land this quickly I guess we can do this naming polish afterwards, but if you have spare cycles maybe you can ask your agent to do the preliminary deduplication of names already in this PR for the most obvious cases?

https://github.com/llvm/llvm-project/pull/226600