Track consumption of command-line args in the rust parser. (pantsbuil…

…d#21410)

So we can error if unrecognized args are found.

This is a current feature of the legacy parser, so this is needed for
compatibility.

src/python/pants/engine/internals/native_engine.pyi

@@ -682,6 +682,7 @@ class PyOptionParser:
     ) -> OptionListValue[str]: ...
     def get_dict(self, option_id: PyOptionId, default: dict[str, Any]) -> OptionDictValue: ...
     def get_passthrough_args(self) -> Optional[list[str]]: ...
+    def get_unconsumed_flags(self) -> list[str]: ...
 
 # ------------------------------------------------------------------------------
 # Testutil

src/python/pants/option/native_options.py

@@ -138,3 +138,6 @@ def is_enum(typ):
                 val = option_type(val)
 
         return (val, rank)
+
+    def get_unconsumed_flags(self) -> tuple[str, ...]:
+        return tuple(self._native_parser.get_unconsumed_flags())

src/python/pants/option/parser.py

@@ -194,7 +194,10 @@ def _create_flag_value_map(flags: Iterable[str]) -> DefaultDict[str, list[str |
                 flag_value_map[key].append(flag_val)
             return flag_value_map
 
-    def parse_args_native(self, native_parser: NativeOptionParser) -> OptionValueContainer:
+    def parse_args_native(
+        self,
+        native_parser: NativeOptionParser,
+    ) -> OptionValueContainer:
         namespace = OptionValueContainerBuilder()
         for args, kwargs in self._option_registrations:
             self._validate(args, kwargs)

src/rust/engine/options/Cargo.toml

@@ -18,6 +18,7 @@ whoami = { workspace = true }
 serde = { workspace = true, features = ["derive"] }
 serde_json = { workspace = true }
 serde_yaml = { workspace = true }
+parking_lot = "0.12.3"
 
 [dev-dependencies]
 tempfile = { workspace = true }