[ELF] - Add testcase for -debugger-tune=<value>
[ELF] - Add testcase for -debugger-tune=<value>

In D42733 we supported different LTO command line
options, including -debugger-tune=<value>.

Initially debugger-tune support was needed to fix PR36035.
Patch adds testcase for this option to check we
don't simply ignore it.

Differential revision: https://reviews.llvm.org/D42961

git-svn-id: f6089bf0e6284f307027cef4f64114ee9ebb0424@324457 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lld,llvm-mirror/lld