Remove duplicated forward declaration.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176536 91177308-0d34-0410-b5e6-96231b3b80d8
Use dyn_cast instead of isa && cast. No functionality change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176537 91177308-0d34-0410-b5e6-96231b3b80d8
Fix PR15355

- Clear 'mayStore' flag when loading from the atomic variable before the
  spin loop
- Clear kill flag from one use to multiple use in registers forming the
  address to that atomic variable
- don't use a physical register as live-in register in BB (neither entry
  nor landing pad.) by copying it into virtual register

(patch by Cameron Zwarich)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176538 91177308-0d34-0410-b5e6-96231b3b80d8