[Acc] Fix for PR33208

During codegen, Polly attempts to clear all loops from ScalarEvolution
and LoopInfo, and it does so one block at a time. This causes undefined
behaviour, since this way a loop header might be removed from a loop
before the entire loop is erased, causing ScalarEvolution to run into an
error.

Instead, just delete the entire loop atomically. This fixes currently
failing testcases.

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@326643 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed