Allow macro_name to be speficied as a parameter to configure_file().
This allows C macro-style include guards to be added to
configure_file()'s output when a template file is not given. This change
simplifies the creation of configure files that define macros with
dynamic names and want the C-style include guards.
We silently dropped all integer values to install_mode since the
original implementation of doing this in KwargInfo, in commit
596c8d4af5.
This happened because install_mode is supposed to convert False
(exactly) to None, and otherwise pass all arguments in place. But a
generator is homogeneous and attempting to do this correctly produced a
mypy error that FileMode arguments were allowed to be ints -- well of
course they are -- so that resulted in the convertor... treating ints
like False instead, to make mypy happy.
Fixes#11538
Stas Sergeev
Nicholas Vinson
Charles Brunet
Eli Schwartz
Dylan Baker
Daniel Mensinger