[ELF] Interp section is only needed in dynamic executables

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@177483 91177308-0d34-0410-b5e6-96231b3b80d8
[ELF][Hexagon] Add Hexagon dynamic relocations

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@177484 91177308-0d34-0410-b5e6-96231b3b80d8