[flang][OpenMP] Map `teams loop` to `teams distribute` when required. (#127489)

This extends support for generic `loop` rewriting by:
1. Preventing nesting multiple worksharing loops inside each other. This
is checked by walking the `teams loop` region searching for any `loop`
directive whose `bind` modifier is `parallel`.
2. Preventing convert to worksharing loop if calls to unknow functions
are found in the `loop` directive's body.

We walk the `teams loop` body to identify either of the above 2
conditions, if either of them is found to be true, we map the `loop`
directive to `distribute`.

0 files changed, 0 insertions, 0 deletions