Add lower level versions of some functions.

This adds versions of getSectionIndex, getSection and getSymbol that
instead of a Elf_Shdr take the content of that section.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285932 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed