[Backport] Do not apply patches if repo is a not a git repo. https://github.com/intel/opencl-clang/pull/539
[Backport] Do not apply patches if sub non-git repo is located in a git repo. https://github.com/intel/opencl-clang/pull/545
Also add an option to control patch apply which is default on. Pass -DAPPLY_PATCHES=OFF will skip patch apply process.
Update LLVM_BASE_REVISION.
[Backport] Do not apply patches if repo is a not a git repo. https://github.com/intel/opencl-clang/pull/539 [Backport] Do not apply patches if sub non-git repo is located in a git repo. https://github.com/intel/opencl-clang/pull/545 Also add an option to control patch apply which is default on. Pass -DAPPLY_PATCHES=OFF will skip patch apply process. Update LLVM_BASE_REVISION.