newline at eof
[CMake] Centralize dependencies to tblgen'd headers with LLVM_COMMON_DEPENDS.

Pros:
  - Easy maintenance. You may edit at most a few CMakefiles to add new *.td.

Cons:
  - Dependencies would not be optimial.
    That said, it would make *.inc(s) regenerated to touch any *.td files.
    (Then, copy_if_diffeent() might save the world, though.)

  - It'd be so tough to maintain and keep dep list in each target.
  - Each *.td depends on other *.td(s) with wildcard. See also TableGen.cmake.
  - Almost every source file depends on any *.td(s).
    In other words, every source file depends on clang-tblgen.
  - clang_tablegen() generates to update *.inc with copy_if_different().
AddLLVM.cmake: Introduce obj.***
lib/Support/CMakeLists.txt: Prune *.inc(s) for now.
[CMake] Use DEPENDS in add_llvm_library().
llvm/utils/unittest/CMakeLists.txt: Add target_link_libraries. are they really needed?
Tweak for CMake's bug.
tweak add_clang_library
DEPEND: Add intrinsics_gen to clang/lib/CodeGen/CMakeLists.txt