[llvm] [IR] Add CallBr intrinsics support (PR #133907)

[Michael Kruse via llvm-commits]

Meinersbur wrote:

That test case was added only to avoid Polly from crashing for some input. 91f46bb77e6d56955c3b96e9e844ae6a251c41e9 reads:
> SplitBlockPredecessors is unable to insert an additional BasicBlock between an indirectbr/callbr terminator and the successor blocks. This is needed by Polly to normalize the control flow before emitting its optimzed code.
> This patches rejects regions entered by an indirectbr/callbr to not fail later at code generation.

I don't understand why you change the region detection code, but I think it just it has the same goal: Don't use regions involving CallBr. With this PR RegionInfo doesn't even return a region, so the check for CallBr becomes unused. You can just change the test to accept the new output. Since it seems there is no output at all, use something like:
```
; RUN: opt %loadNPMPolly '-passes=print<polly-detect>' -disable-output < %s 2>&1 | FileCheck %s
; CHECK-LABEL: func
; CHECK-NOT: Valid
```


https://github.com/llvm/llvm-project/pull/133907