[ELF] Set the symbol type for undefined atoms properly

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@178466 91177308-0d34-0410-b5e6-96231b3b80d8
[ELF][Hexagon] Create .got.plt entries with the appropriate alignment

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@178467 91177308-0d34-0410-b5e6-96231b3b80d8