DebugInfo: Remove distinct-call-inlining test case as this is being fixed in LLVM.

This test will start failing shortly once this bug is fixed in LLVM. At
that point this behavior is no longer required in Clang and will be
removed. In the interim, remove this test just to avoid the race between
the LLVM and Clang commits.

After the LLVM commit, I'll cleanup the workaround behavior in Clang.

llvm-svn: 226735