This patch fixes the following compiler error:
error: declaration of ‘mlir::LLVM::cconv::CConv mlir::LLVM::detail::CConvAttrStorage::CConv’ changes meaning of ‘CConv’ [-fpermissive]
CConv as a member variable name was shadowing CConv as an enumeration,
hence the compiler error.
Reviewed By: ftynse, alexbatashev
Differential Revision: https://reviews.llvm.org/D126530