Fork improvements

• Make it easier to attach schedules to reduce nodes.
  • User can attach schedule to init or reduct inputs and appropriate schedule will get propagated to reduce node.
• Persist tmp directories when clang, nvcc, or ar fail.
• Add new fork test.

requested review from @xrouth2

assigned to @rarbore2

added 1 commit

• 40b1a705 - fix

Compare with previous version

merged

mentioned in commit 84efde04