Remove the SplitDebug action and replace with a set of commands
in the compilation setup. Note that this doesn't currently
work for -no-integrated-as.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175813 91177308-0d34-0410-b5e6-96231b3b80d8
Don't pass -split-dwarf= to the backend unless we're on linux for
now.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175814 91177308-0d34-0410-b5e6-96231b3b80d8
Fix formatting and tabs in file.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@175815 91177308-0d34-0410-b5e6-96231b3b80d8