[ELF][X86_64][Hexagon] order plt/got entries properly and fix test

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@176970 91177308-0d34-0410-b5e6-96231b3b80d8
[lld] remove trailing whitespace

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@177079 91177308-0d34-0410-b5e6-96231b3b80d8
yay multithreading.
Set ordinals correctly.
Devirtualize File::kind.
Devirtualize Reference::kind.
Threading!
memcpy instead of copy_n. Faster than copy_n on MSVC :(.