add hexagon target to lld

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@172202 91177308-0d34-0410-b5e6-96231b3b80d8
add noinhibit exec option

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@172204 91177308-0d34-0410-b5e6-96231b3b80d8