tree 6e743ad6e90eda9e3509dff4b9f50038fa8733c7
parent 2552de030bb50ab793ff8851401214187d35b542
author Chandler Carruth <chandlerc@gmail.com> 1322124364 +0000
committer Chandler Carruth <chandlerc@gmail.com> 1322124364 +0000

When adding blocks to the list of those which no longer have any CFG
conflicts, we should only be adding the first block of the chain to the
list, lest we try to merge into the middle of that chain. Most of the
places we were doing this we already happened to be looking at the first
block, but there is no reason to assume that, and in some cases it was
clearly wrong.

I've added a couple of tests here. One already worked, but I like having
an explicit test for it. The other is reduced from a test case Duncan
reduced for me and used to crash. Now it is handled correctly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145119 91177308-0d34-0410-b5e6-96231b3b80d8