This reverts commit da6318a92fba793e4f2447ec478b001392d57d43.
This is causing failures on some build bots due to what appears
to be some kind of lit ordering dependency.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306833 91177308-0d34-0410-b5e6-96231b3b80d8
Presently lit leaks files in the tests' output directories.
Specifically, if a test creates output files, lit makes no
effort to remove them prior to the next test run. This is
problematic because it leads to false positives whenever a
test passes because stale files were present. In general
it is a source of flakiness that should be removed.
This patch addresses this by building the list of all test
directories that are part of the current run set, and then
deleting those directories and recreating them anew. This
gives each test a clean baseline to start from.
Differential Revision: https://reviews.llvm.org/D34732
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306832 91177308-0d34-0410-b5e6-96231b3b80d8
