This should fix this error which appears on RHEL only:
```
Configuration error:
There is a programmable error in your configuration file:
Traceback (most recent call last):
File "/usr/lib/python3.9/site-packages/sphinx/config.py", line 326, in eval_config_file
execfile_(filename, namespace)
File "/usr/lib/python3.9/site-packages/sphinx/util/pycompat.py", line 88, in execfile_
exec(code, _globals)
File "/builddir/build/BUILD/llvm-project-c1d5cc99c6ba8e897ea145dbb2221a155b5e3e5a/llvm/redhat-linux-build/tools/clang/docs/conf.py", line 42, in <module>
import myst_parser
ModuleNotFoundError: No module named 'myst_parser'
```
See also https://github.com/fedora-llvm-team/llvm-snapshots/issues/492
* %check: export LD_LIBRARY_PATH because runtimes use external cmake projects that wouldn't find libclang++.so
* %check: use LLVM's LIT_XFAIL to mark tests that are expected to fail and don't just delete them
* clang: bring over *.patch files
* clang: remove build requires tags from clang package that are already defined by main llvm package
* clang: remove duplicates found in llvm globals and use %{pkg_datadir} instead of %{install_datadir}
* clang: rename and use pkg_name -> pkg_name_clang
* clang: use %{pkg_name_clang} instead of %{name}
* compiler-rt and libomp: wrap in %if %{without compat_build}
* libomp: also build libomp for s390x (See https://github.com/llvm/llvm-project/pull/66081)
* libomp: exclude libomp-devel on s390x just like libomp itself
* libomp: introduce pkg_name_libomp and cleanup the globals
* libomp: remove gdb-plugin (NEED TO CONFIRM IF THIS IS REALLY TRUE)
* libomp: filter out flaky libomp test: ompt/teams/distribute_dispatch.c
* llvm: add BuildRequires: graphviz to llvm-doc
* llvm: use %{pkg_name_llvm} instead of %{name}
* make: added temporary Makefile so I can more easily run srpm or rpm builds locally
* make: Added local-tmt-vm target (not really useful yet)
* rpm: for non-RHEL add prefix like "Jan 05 16:17:06" to every log line This should help in finding out how long things take to build/install/...
* rpm: fully specify %files for top-level packages
* rpm: make all packages fully qualified
* rpm: obsolete llvm-snapshot-builder
* rpm: remove BuildRequires: python3-lit because we have it in-tree
* rpm: remove BuildRequires: tags for clang and llvm specifics as we're building in-tree
* rpm: rename %llvm_srcdir -> %srcdir_llvm
* rpm: rename %pkg_name -> %pkg_name_llvm
* rpm: use full qualified name in %description
* rpm: use region comments in spec file to group by package. This allows editors to fold text to get a better overview
* rpmlint: update rc file to reflect clang and compiler-rt (libomp has no rpmlint rc file)
* use python-lit from within tree
