Added scripts/get_coverage.py

Usage:

```
python scripts/gen_coverage.py
```

Builds coverage binaries, runs both ctests and pytest

Allowed options can be retrived with `python scripts/gen_coverage.py --help`.
Only Linux is supported, dependencies are assumed to be available.

Author: oleksandr-pavlyk

scripts/gen_coverage.py

@@ -0,0 +1,157 @@
+import os
+import subprocess
+import sys
+
+
+def run(
+    use_oneapi=True,
+    c_compiler=None,
+    cxx_compiler=None,
+    level_zero=True,
+    compiler_root=None,
+    run_pytest=False,
+    bin_llvm=None,
+):
+    IS_LIN = False
+
+    if "linux" in sys.platform:
+        IS_LIN = True
+    elif sys.platform in ["win32", "cygwin"]:
+        pass
+    else:
+        assert False, sys.platform + " not supported"
+
+    if not IS_LIN:
+        raise RuntimeError(
+            "This scripts only supports coverage collection on Linux"
+        )
+    setup_dir = os.path.dirname(os.path.dirname(__file__))
+    cmake_args = [
+        sys.executable,
+        "setup.py",
+        "develop",
+        "--",
+        "-G",
+        "Unix Makefiles",
+        "-DCMAKE_BUILD_TYPE=Debug",
+        "-DCMAKE_C_COMPILER:PATH=" + c_compiler,
+        "-DCMAKE_CXX_COMPILER:PATH=" + cxx_compiler,
+        "-DDPCTL_ENABLE_LO_PROGRAM_CREATION=" + ("ON" if level_zero else "OFF"),
+        "-DDPCTL_GENERATE_COVERAGE=ON",
+        "-DDPCTL_BUILD_CAPI_TESTS=ON",
+        "-DDPCTL_COVERAGE_REPORT_OUTPUT_DIR=" + setup_dir,
+        "-DDPCTL_DPCPP_FROM_ONEAPI:BOOL=" + ("ON" if use_oneapi else "OFF"),
+    ]
+    if compiler_root:
+        cmake_args += [
+            "-DDPCTL_DPCPP_HOME_DIR:PATH=" + compiler_root,
+        ]
+    env = None
+    if bin_llvm:
+        env = {
+            "PATH": ":".join((os.environ.get("PATH", ""), bin_llvm)),
+        }
+        env.update({k: v for k, v in os.environ.items() if k != "PATH"})
+    subprocess.check_call(cmake_args, shell=False, cwd=setup_dir, env=env)
+    test_dir = (
+        subprocess.check_output(
+            ["find", "_skbuild", "-name", "tests"], cwd=setup_dir
+        )
+        .decode("utf-8")
+        .strip("\n")
+    )
+    subprocess.check_call(
+        ["make", "-C", test_dir, "lcov-genhtml"], cwd=setup_dir
+    )
+    subprocess.check_call(
+        [
+            "pytest",
+            "-q",
+            "-ra",
+            "--disable-warnings",
+            "--cov-config",
+            "pyproject.toml",
+            "--cov",
+            "dpctl",
+            "--cov-report",
+            "term-missing",
+            "--pyargs",
+            "dpctl",
+            "-vv",
+        ],
+        cwd=setup_dir,
+        shell=False,
+    )
+
+
+if __name__ == "__main__":
+    import argparse
+
+    parser = argparse.ArgumentParser(
+        description="Driver to build dpctl and generate coverage"
+    )
+    driver = parser.add_argument_group(title="Coverage driver arguments")
+    driver.add_argument("--c-compiler", help="Name of C compiler", default=None)
+    driver.add_argument(
+        "--cxx-compiler", help="Name of C++ compiler", default=None
+    )
+    driver.add_argument(
+        "--not-oneapi",
+        help="Is one-API installation",
+        dest="oneapi",
+        action="store_false",
+    )
+    driver.add_argument(
+        "--compiler-root", type=str, help="Path to compiler home directory"
+    )
+    driver.add_argument(
+        "--no-level-zero",
+        help="Enable Level Zero support",
+        dest="level_zero",
+        action="store_false",
+    )
+    driver.add_argument(
+        "--skip-pytest",
+        help="Run pytest and collect coverage",
+        dest="run_pytest",
+        action="store_false",
+    )
+    driver.add_argument(
+        "--bin-llvm", help="Path to folder where llvm-cov can be found"
+    )
+    args = parser.parse_args()
+
+    if args.oneapi:
+        args.c_compiler = "icx"
+        args.cxx_compiler = "icpx"
+        args.compiler_root = None
+        icx_path = subprocess.check_output(["which", "icx"])
+        bin_dir = os.path.dirname(os.path.dirname(icx_path))
+        args.bin_llvm = os.path.join(bin_dir.decode("utf-8"), "bin-llvm")
+    else:
+        args_to_validate = [
+            "c_compiler",
+            "cxx_compiler",
+            "compiler_root",
+            "bin_llvm",
+        ]
+        for p in args_to_validate:
+            arg = getattr(args, p, None)
+            if not isinstance(arg, str):
+                opt_name = p.replace("_", "-")
+                raise RuntimeError(
+                    f"Option {opt_name} must be provided is "
+                    "using non-default DPC++ layout"
+                )
+            if not os.path.exists(arg):
+                raise RuntimeError(f"Path {arg} must exist")
+
+    run(
+        use_oneapi=args.oneapi,
+        c_compiler=args.c_compiler,
+        cxx_compiler=args.cxx_compiler,
+        level_zero=args.level_zero,
+        compiler_root=args.compiler_root,
+        run_pytest=args.run_pytest,
+        bin_llvm=args.bin_llvm,
+    )