[Hexagon][CI] Re-enable Hexagon tests in CI

These were enabled in apache#11294, then
erroneously disabled in apache#11313.
This applies the same fix as in
apache#11294, checking the
`ANDROID_SERIAL_NUMBER` to determine if Hexagon tests can execute at
runtime, but using the refactored `pytest.skipif` messages introduced
in apache#11313.

python/tvm/contrib/hexagon/pytest_plugin.py

@@ -26,6 +26,7 @@
 import pytest
 
 import tvm
+import tvm.testing
 import tvm.rpc.tracker
 from tvm.contrib.hexagon.build import HexagonLauncher, HexagonLauncherRPC
 from tvm.contrib.hexagon.session import Session
@@ -53,15 +54,36 @@ def _compose(args, decs):
     return decs
 
 
-def requires_hexagon_toolchain(*args):
-    _requires_hexagon_toolchain = [
-        pytest.mark.skipif(
-            os.environ.get(HEXAGON_TOOLCHAIN) is None,
-            reason=f"Missing environment variable {HEXAGON_TOOLCHAIN}.",
-        ),
-    ]
+def _compile_time_check():
+    """Return True if compile-time support for Hexagon is present, otherwise
+    error string.
 
-    return _compose(args, _requires_hexagon_toolchain)
+    Designed for use as a the ``compile_time_check`` argument to
+    `tvm.testing.Feature`.
+    """
+    if _cmake_flag_enabled("USE_LLVM") and tvm.target.codegen.llvm_version_major() < 7:
+        return "Hexagon requires LLVM 7 or later"
+
+    if "HEXAGON_TOOLCHAIN" not in os.environ:
+        return f"Missing environment variable {HEXAGON_TOOLCHAIN}."
+
+    return True
+
+
+def _run_time_check():
+    """Return True if run-time support for Hexagon is present, otherwise
+    error string.
+
+    Designed for use as a the ``run_time_check`` argument to
+    `tvm.testing.Feature`.
+    """
+    if ANDROID_SERIAL_NUMBER not in os.environ:
+        return f"Missing environment variable {ANDROID_SERIAL_NUMBER}."
+
+    return True
+
+
+requires_hexagon_toolchain = tvm.testing.requires_hexagon(support_required="compile-only")
 
 
 @tvm.testing.fixture

python/tvm/testing/utils.py

@@ -88,6 +88,7 @@ def test_something():
 import tvm._ffi
 
 from tvm.contrib import nvcc, cudnn
+from tvm.contrib.hexagon import pytest_plugin as hexagon
 from tvm.error import TVMError
 
 
@@ -937,11 +938,8 @@ def _any_gpu_exists():
     "Hexagon",
     cmake_flag="USE_HEXAGON",
     target_kind_enabled="hexagon",
-    compile_time_check=lambda: (
-        (_cmake_flag_enabled("USE_LLVM") and tvm.target.codegen.llvm_version_major() >= 7)
-        or "Hexagon requires LLVM 7 or later"
-    ),
-    target_kind_hardware="hexagon",
+    compile_time_check=hexagon._compile_time_check,
+    run_time_check=hexagon._run_time_check,
     parent_features="llvm",
 )