Bugfix/multiple ptxas options values (#678)

* Correctly handle multiple values of ptxas_options

The correct way to handle multiple options is to pass them
to NVRTC one at a time, e.g.,

```
--ptxas-options=val1 --ptxas-options=val2
```

* Test single and multiple values of ptxas_options in ProgramOptions

Author: oleksandr-pavlyk

cuda_core/cuda/core/experimental/_program.py

@@ -242,12 +242,12 @@ def __post_init__(self):
         if self.device_code_optimize is not None:
             self._formatted_options.append(f"--dopt={'on' if self.device_code_optimize else 'off'}")
         if self.ptxas_options is not None:
-            self._formatted_options.append("--ptxas-options")
+            opt_name = "--ptxas-options"
             if isinstance(self.ptxas_options, str):
-                self._formatted_options.append(self.ptxas_options)
+                self._formatted_options.append(f"{opt_name}={self.ptxas_options}")
             elif is_sequence(self.ptxas_options):
-                for option in self.ptxas_options:
-                    self._formatted_options.append(option)
+                for opt_value in self.ptxas_options:
+                    self._formatted_options.append(f"{opt_name}={opt_value}")
         if self.max_register_count is not None:
             self._formatted_options.append(f"--maxrregcount={self.max_register_count}")
         if self.ftz is not None:

cuda_core/tests/test_program.py

@@ -43,6 +43,8 @@ def ptx_code_object():
         ProgramOptions(diag_error=1234, diag_suppress=1234),
         ProgramOptions(diag_error=[1234, 1223], diag_suppress=(1234, 1223)),
         ProgramOptions(diag_warn=1000),
+        ProgramOptions(std="c++11", ptxas_options=["-v"]),
+        ProgramOptions(std="c++11", ptxas_options=["-v", "-O2"]),
     ],
 )
 def test_cpp_program_with_various_options(init_cuda, options):