Speculatively revert commit 144124 (djg) in the hope that the 32 bit

dragonegg self-host buildbot will recover (it is complaining about object
files differing between different build stages).  Original commit message:

Add a hack to the scheduler to disable pseudo-two-address dependencies in
basic blocks containing calls. This works around a problem in which
these artificial dependencies can get tied up in calling seqeunce
scheduling in a way that makes the graph unschedulable with the current
approach of using artificial physical register dependencies for calling
sequences. This fixes PR11314.

llvm-svn: 144188