Revert "[DWARF] reposting r342048, which was reverted in r342056 due to...

Revert "[DWARF] reposting r342048, which was reverted in r342056 due to buildbot errors. Adjusted 2 test cases for ARM and darwin and fixed a bug with the original change in dsymutil."

This reverts commit r342218. Due to a number of failures under TSAN. An isolated
test case is being worked on.

llvm-svn: 342399