[Object/ELF] - Check Header->e_shoff value earlier and do not crash.

Patch checks that section pointer is aligned properly.
This should be done before getStringTable() call.

Differential revision: https://reviews.llvm.org/D25462

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284387 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed