llvm minor version is required: 18.1

Revert "add 'Visibility' field to Option (intel#474)"

This reverts commit 45180f6.

Update README.md (intel#414)

[CI] Prepare release branch for LLVM 15 (intel#375)

Signed-off-by: Haonan Yang <haonan.yang@intel.com>

Update for ocl-open-140 branch (intel#327)

1. Update version number and branch names
2. Enable Github Actions
3. Fix build errors

Signed-off-by: Haonan Yang <haonan.yang@intel.com>

Merge pull request intel#273 from haonanya/ocl-130-branch-creared

Update version number and branch names for ocl-open-130 branch

Merge pull request intel#242 from haonanya/haonanya/remove-image-supp…

…ort-120

Remove __IMAGE_SUPPORT__ macro for SPIR

Merge pull request intel#208 from fzou1/remove-repo-name-110

Remove repo name in LLVM IR for ocl-open-110 branch

opencl-clang linked against LLVM 10 libraries

Link with libclang-cpp for out-of-tree build

Signed-off-by: Alexey Sotkin <alexey.sotkin@intel.com>