Revert "[DebugInfo][RemoveDIs] Turn on non-instrinsic debug-info by default"

This reverts commit bdde5f9b.

Two situations that are tripping a few buildbots:

  https://lab.llvm.org/buildbot/#/builders/205/builds/25126

Here, polly is currently presenting a DebugLoc attached to a debugging
intrinsic as a "true" source location in a user report, something that's
unreliable.

  https://lab.llvm.org/buildbot/#/builders/184/builds/10242

These HWAsan failures are probably (97% confidence) because in
StackInfoBuilder::visit we're not observing DPValues attached to lifetime
intrinsics because they're delt with higher up the function.

But it's late-o'clock here, so revert for now.