[RUNTIME] Major code cleanup (#711)

This PR does the following:
- CUDA utilities (e.g., cuGetInfo) won't be compiled as part of libtriton.so anymore.
- Refactoring driver/llvm.cc to split it between PTX codegen and python.
- By extension this will also deprecate include/external so Triton won't have to live with a copy of some CUDA/Hip headers anymore.
- `triton-translate` becomes a `triton.tools.aot` Python utility that re-uses functions from the triton.compile sub-module.

lib/Target/LLVMIR/LLVMIRTranslation.cpp

@@ -13,7 +13,6 @@
 #include "mlir/Target/LLVMIR/LLVMTranslationInterface.h"
 #include "mlir/Transforms/Passes.h"
 #include "triton/Conversion/TritonGPUToLLVM/TritonGPUToLLVM.h"
-#include "triton/driver/llvm.h"
 #include "triton/tools/sys/getenv.hpp"
 #include "llvm/IR/Constants.h"
 
@@ -99,7 +98,6 @@ translateLLVMToLLVMIR(llvm::LLVMContext *llvmContext, mlir::ModuleOp module) {
   }
 
   // Initialize LLVM targets.
-  ::triton::driver::init_llvm();
   mlir::ExecutionEngine::setupTargetTriple(llvmModule.get());
 
   auto optPipeline = mlir::makeOptimizingTransformer(