[Refactor][NFC] Vendor-in numba.cpython modules for future CUDA-specific changes (#493)

This is a bulk change that vendors in all of the modules in
numba.cpython without tests to prevent blocking of other components that
need to be vendored in. All of the relevant tests will be vendored in
gradually in other PRs once it becomes a higher priority to ensure
comprehensive test coverage.

---------

Co-authored-by: Graham Markall <[email protected]>

Author: atmnp

numba_cuda/numba/cuda/core/inline_closurecall.py

@@ -1088,7 +1088,7 @@ def length_of_iterator(typingctx, val):
 
         def codegen(context, builder, sig, args):
             (value,) = args
-            from numba.cpython.rangeobj import range_impl_map
+            from numba.cuda.cpython.rangeobj import range_impl_map
 
             iter_type = range_impl_map[val_type][1]
             iterobj = cgutils.create_struct_proxy(iter_type)(

numba_cuda/numba/cuda/core/interpreter.py

@@ -24,7 +24,7 @@
 from numba.cuda.utils import _lazy_pformat
 from numba.cuda.core.byteflow import Flow, AdaptDFA, AdaptCFA, BlockKind
 from numba.cuda.core.unsafe import eh
-from numba.cpython.unsafe.tuple import unpack_single_tuple
+from numba.cuda.cpython.unsafe.tuple import unpack_single_tuple
 
 
 if PYVERSION in ((3, 12), (3, 13)):