Previous version used type erasure through a `void* (*)()` pointer,
which triggered gcc warning and implied a lot of reinterpret_cast.
This version should make it harder to hit ourselves in the foot.
Differential revision: https://reviews.llvm.org/D54203
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346522 91177308-0d34-0410-b5e6-96231b3b80d8
2. Added argument to instruction scheduler creators so the creators can do
special things.
3. Repaired target hazard code.
4. Misc.
More to follow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@29450 91177308-0d34-0410-b5e6-96231b3b80d8
