Re-add the autoconf rule for the docs/doxygen.cfg file.
For some reason this was not reverted when r103213 was.

At the same time, add an optional rule for clang's doxygen.cfg.

llvm-svn: 131279
2 files changed
tree: 73f7bf4e2b2e62946139aa3a3cbb49a6352021af
  1. clang/
  2. compiler-rt/
  3. debuginfo-tests/
  4. libcxx/
  5. libcxxabi/
  6. lldb/
  7. llvm/
  8. polly/