Several Changes To Support Building llvm-config:
1. If Perl is not available, don't run Perl dependent targets.
2. Check in FinalLibDeps.txt for build environments that can't build it
   because there's no Perl processor.
3. Ensure that FinalLibDeps.txt depends on LibDeps.txt so it is
   automatically regenerated.
4. Support objdir != srcdir building.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27915 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed