Page missing, but mentioned in README

[lopippo]

Greetings,

the https://github.com/intel/llvm#late-outline-openmp-and-openmp-offload page mentions an URL that is missing:

See openmp branch.

Sincerely, Filippo

[AlexeySachkov]

It seems like link points to a file, whilst it should point to a branch instead.

However, considering that there is only one commit (which is two years old already), we may want to remove that section all together. sycl-mlir is a better example of an open-source LLVM-based project we have.