force add attribute not EnumAttr

[lifengxiang1025]

I want to force add attribute not EnumAttr like "use-sample-profile". But llvm doesn't support now. https://github.com/llvm/llvm-project/blob/main/llvm/lib/Transforms/IPO/ForceFunctionAttrs.cpp#L62C1-L62C63. Why llvm need to check the attribute? Can we force add attribute as string without checking?

[lifengxiang1025]

Hi, @boomanaiden154 @nikic What do you think?