Adds a kernel_iface module in experimental.

    - A new experimental module kernel_iface was added to
      store Python implementation of the kernel API. The
      initial module has the memory enum classes that can
      be used as flags in a numba_dpex.experimental.kernel

Author: Diptorup Deb

numba_dpex/experimental/kernel_iface/__init__.py

@@ -0,0 +1,13 @@
+# SPDX-FileCopyrightText: 2023 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+"""The kernel_iface provides a set of Python classes and functions that are
+analogous to the C++ SYCL API. The kernel_iface API is meant to allow
+prototyping SYCL-like kernels in pure Python before compiling them using
+numba_dpex.kernel.
+"""
+
+from .memory_enums import AddressSpace, MemoryOrder, MemoryScope
+
+__all__ = ["AddressSpace", "MemoryOrder", "MemoryScope"]

numba_dpex/experimental/kernel_iface/memory_enums.py

@@ -0,0 +1,79 @@
+# SPDX-FileCopyrightText: 2023 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+"""A collection of FlagEnum classes that syntactically represents the SYCL
+memory enum classes.
+"""
+
+from numba_dpex.experimental.flag_enum import FlagEnum
+
+
+class MemoryOrder(FlagEnum):
+    """
+    An enumeration of the supported ``sycl::memory_order`` values in dpcpp. The
+    integer values of the enums is kept consistent with the corresponding
+    implementation in dpcpp.
+
+    =====================   ============
+    Order                   Enum value
+    =====================   ============
+    RELAXED                 0
+    ACQUIRE                 1
+    CONSUME_UNSUPPORTED     2
+    RELEASE                 3
+    ACQ_REL                 4
+    SEQ_CST                 5
+    =====================   ============
+    """
+
+    RELAXED = 0
+    ACQUIRE = 1
+    CONSUME_UNSUPPORTED = 2
+    RELEASE = 3
+    ACQ_REL = 4
+    SEQ_CST = 5
+
+
+class MemoryScope(FlagEnum):
+    """
+    An enumeration of SYCL memory scope. For more details please refer to
+    SYCL 2020 specification, section 3.8.3.2
+
+    ===============  ============
+    Memory Scope     Enum value
+    ===============  ============
+    WORK_ITEM        0
+    SUB_GROUP        1
+    WORK_GROUP       2
+    DEVICE           3
+    SYSTEM           4
+    ===============  ============
+    """
+
+    WORK_ITEM = 0
+    SUB_GROUP = 1
+    WORK_GROUP = 2
+    DEVICE = 3
+    SYSTEM = 4
+
+
+class AddressSpace(FlagEnum):
+    """The address space values supported by numba_dpex.
+
+    ==================   ============
+    Address space        Value
+    ==================   ============
+    PRIVATE              0
+    GLOBAL               1
+    CONSTANT             2
+    LOCAL                3
+    GENERIC              4
+    ==================   ============
+    """
+
+    PRIVATE = 0
+    GLOBAL = 1
+    CONSTANT = 2
+    LOCAL = 3
+    GENERIC = 4