This patch adds a new NVPTX back-end to LLVM which supports code generation for NVIDIA PTX 3.0. This back-end will (eventually) replace the current PTX back-end, while maintaining compatibility with it.

The new target machines are:

nvptx (old ptx32) => 32-bit PTX
nvptx64 (old ptx64) => 64-bit PTX

The sources are based on the internal NVIDIA NVPTX back-end, and
contain more functionality than the current PTX back-end currently
provides.

NV_CONTRIB

llvm-svn: 156196

llvm-svn: 153307

subdirectories to traverse into.
 - Originally I wanted to avoid this and just autoscan, but this has one key
   flaw in that new subdirectories can not automatically trigger a rerun of the
   llvm-build tool. This is particularly a pain when switching back and forth
   between trees where one has added a subdirectory, as the dependencies will
   tend to be wrong. This will also eliminates FIXME implicitly.

llvm-svn: 146436

llvm-svn: 144415

options to llvm-build, so the all-targets etc. components are defined properly.

llvm-svn: 144255

handle defining the "magic" target related components (like native,
nativecodegen, and engine).
 - We still require these components to be in the project (currently in
   lib/Target) so that we have a place to document them and hopefully make it
   more obvious that they are "magic".

llvm-svn: 144253

llvm-svn: 143634