Add support for rust cfg response file #2
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Add support to write the rustc_cfg response file via write_rustcfg. This is equivalent to the rust response file used for rust support in the kernel as introduced in
2f7ab1267dc9b2d1f29695aff3211c87483480f3 in the kernel tree.
Link: https://lore.kernel.org/rust-for-linux/[email protected]/#Z31scripts:kconfig:confdata.c
This implements the response file generator as mentioned in zephyrproject-rtos/zephyr#65837 (comment)