When redefining a macro don't warn twice if it's not used and don't warn for duplicate
definition by command line options. Fixes rdar://8875916.

llvm-svn: 123767
2 files changed
tree: 71f355c1eba190e4b43f80aab53c5000dc00819e
  1. clang/
  2. compiler-rt/
  3. debuginfo-tests/
  4. libcxx/
  5. lldb/
  6. llvm/