Revert r213415, "Merge two lines". It broke tests in -Asserts builds.

CGBuilder doesn't name instructions with Name. We should use Inst::setName() to name an instruction explicitly here.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@213431 91177308-0d34-0410-b5e6-96231b3b80d8