Log Message:
LLVM 2.9 includes several major new capabilities:
* Type Based Alias Analysis (TBAA) is now implemented and turned on by default
  in Clang. This allows substantially better load/store optimization in some
  cases. TBAA can be disabled by passing -fno-strict-aliasing.
* This release has seen a continued focus on quality of debug information. LLVM
  now generates much higher fidelity debug information, particularly when
  debugging optimized code.
* Inline assembly now supports multiple alternative constraints.
* A new backend for the NVIDIA PTX virtual ISA (used to target its GPUs) is
  under rapid development. It is not generally useful in 2.9, but is making
  rapid progress.