Use HPy NFI backend by default for benchmarks

Author: fangerer

mx.graalpython/mx_graalpython.py

@@ -1578,20 +1578,21 @@ def _register_vms(namespace):
         '--llvm.managed', '--python.PosixModuleBackend=java'
     ]), SUITE, 10)
     python_vm_registry.add_vm(GraalPythonVm(config_name=CONFIGURATION_NATIVE, extra_polyglot_args=[
+        '--experimental-options', '--python.HPyBackend=NFI'
     ]), SUITE, 10)
     python_vm_registry.add_vm(GraalPythonVm(config_name=CONFIGURATION_NATIVE_INTERPRETER, extra_polyglot_args=[
-        '--experimental-options', '--engine.Compilation=false']), SUITE, 10)
+        '--experimental-options', '--engine.Compilation=false', '--python.HPyBackend=NFI']), SUITE, 10)
     python_vm_registry.add_vm(GraalPythonVm(config_name=CONFIGURATION_SANDBOXED_MULTI, extra_polyglot_args=[
         '--experimental-options', '-multi-context', '--llvm.managed', '--python.PosixModuleBackend=java'
     ]), SUITE, 10)
     python_vm_registry.add_vm(GraalPythonVm(config_name=CONFIGURATION_NATIVE_MULTI, extra_polyglot_args=[
-        '--experimental-options', '-multi-context',
+        '--experimental-options', '-multi-context', '--python.HPyBackend=NFI'
     ]), SUITE, 10)
     python_vm_registry.add_vm(GraalPythonVm(config_name=CONFIGURATION_NATIVE_INTERPRETER_MULTI, extra_polyglot_args=[
-        '--experimental-options', '-multi-context', '--engine.Compilation=false',
+        '--experimental-options', '-multi-context', '--engine.Compilation=false', '--python.HPyBackend=NFI'
     ]), SUITE, 10)
     python_vm_registry.add_vm(GraalPythonVm(config_name=CONFIGURATION_NATIVE_MULTI_TIER, extra_polyglot_args=[
-        '--experimental-options', '--engine.MultiTier=true',
+        '--experimental-options', '--engine.MultiTier=true', '--python.HPyBackend=NFI'
     ]), SUITE, 10)
 
     # java embedding driver