inalloca: Fix incorrect example IR and remove LangRef warning

The LangRef warning wasn't formatting the way I intended it to anyway.

Surprisingly inalloca appears to work, even when optimizations are
enabled.  We generate very bad code for it, but we can self-host and run
lots of big tests.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204888 91177308-0d34-0410-b5e6-96231b3b80d8