[clang] [OpenMP][Clang] Parsing support for num_teams lower bound (PR #180608)

[Zahira Ammarguellat via cfe-commits]

zahiraam wrote:

I don't think you need to separate the LIT tests for lower and upper bound. You should have a LIT test called `num_teams_clause_messages.cpp` that will basically a copy of your `num_teams_lower_bound_error_test.cpp`. You also need to have one called `num_teams_clause_ast.cpp` that dumps the `AST` and finally one called `num_teams_clause_codegen.cpp` that checks the resulting IR.

https://github.com/llvm/llvm-project/pull/180608