Revert "[llvm-dsymutil] Add support for __swift_ast MachO DWARF section"

Breaks aarch64 builders

This reverts commit r315014.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@315034 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed