[ELF] Read IFUNC symbols correctly as typeResolver.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@173299 91177308-0d34-0410-b5e6-96231b3b80d8
Add SectionPosition and OrderPass

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@173300 91177308-0d34-0410-b5e6-96231b3b80d8