modules: Add a method to the state object for include_dirs

The Interpreter has a method for this, and the module state just wraps
it.

mesonbuild/modules/__init__.py

@@ -19,8 +19,9 @@ import dataclasses
 import typing as T
 
 from .. import mesonlib
-from ..mesonlib import relpath, HoldableObject, MachineChoice
+from ..build import IncludeDirs
 from ..interpreterbase.decorators import noKwargs, noPosargs
+from ..mesonlib import relpath, HoldableObject, MachineChoice
 from ..programs import ExternalProgram
 
 if T.TYPE_CHECKING:
@@ -151,6 +152,19 @@ class ModuleState:
         key = mesonlib.OptionKey(name, subproject, machine, lang, module)
         return key in self._interpreter.user_defined_options.cmd_line_options
 
+    def process_include_dirs(self, dirs: T.Iterable[T.Union[str, IncludeDirs]]) -> T.Iterable[IncludeDirs]:
+        """Convert raw include directory arguments to only IncludeDirs
+
+        :param dirs: An iterable of strings and IncludeDirs
+        :return: None
+        :yield: IncludeDirs objects
+        """
+        for d in dirs:
+            if isinstance(d, IncludeDirs):
+                yield d
+            else:
+                yield self._interpreter.build_incdir_object([d])
+
 
 class ModuleObject(HoldableObject):
     """Base class for all objects returned by modules