Unix/Host.inc: Remove leading whitespace. It had been here since r56942!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218370 91177308-0d34-0410-b5e6-96231b3b80d8
Unix/Host.inc: Wrap a comment line in 80-col.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218371 91177308-0d34-0410-b5e6-96231b3b80d8
Unix/Host.inc: Remove <cstdlib>. It has been unused for a long time.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218373 91177308-0d34-0410-b5e6-96231b3b80d8
Windows/Host.inc: Reformat the header to fit 80-col.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218374 91177308-0d34-0410-b5e6-96231b3b80d8