Revert to heuristical DebugLoc finding

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@215623 91177308-0d34-0410-b5e6-96231b3b80d8
Do not assert when trying to replace the log with another log

This usually happens when TempScopInfo calls isMaxRegionInScop(..),
so don't fail there.

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@215624 91177308-0d34-0410-b5e6-96231b3b80d8
Use a snapshot of the aliasing pointers

Store the llvm::Value pointers of the AliasSet instead of the AliasSet
itself.

We have to be careful about changed IR when the message is generated,
because the Value pointers might not exist anymore. This would render
the Diagnostic invalid. For now we just assert there.

Simply do not retreive a diagnostic message after the IR has changed
it's not valid information anyway.

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@215625 91177308-0d34-0410-b5e6-96231b3b80d8
Cleanup RejectLog code

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@215626 91177308-0d34-0410-b5e6-96231b3b80d8
Add print method to RejectLog

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@215627 91177308-0d34-0410-b5e6-96231b3b80d8