compilers: do accept None in Compiler.compile extra_args
The type information allows it, but it is not actually handled.
@@ -791,6 +791,7 @@ class Compiler(HoldableObject, metaclass=abc.ABCMeta):
# extra_args must be last because it could contain '/link' to
# pass args to VisualStudio's linker. In that case everything
# in the command line after '/link' is given to the linker.
+ if extra_args:
commands += extra_args
# Generate full command-line with the exelist
command_list = self.get_exelist() + commands.to_native()
