Object/LLVMBuild.txt: Sort required_libraries by alphabetical order.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212917 91177308-0d34-0410-b5e6-96231b3b80d8
NVPTX/LLVMBuild.txt: Add "Scalar" to required_libraries. It is really referenced.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212918 91177308-0d34-0410-b5e6-96231b3b80d8