When end-user crates provide a panic handler, this symbol is not needed ... but the linker isn't smart enough to optimize it away, even though the PROVIDE line isn't used (the symbol is provided by the rust function tagged with #[panic_handler]). Those crates can enable this feature to remove the PROVIDE line from the linker script, to stop linking this default panic handler.
When end-user crates provide a panic handler, this symbol is not needed ... but the linker isn't smart enough to optimize it away, even though the PROVIDE line isn't used (the symbol is provided by the rust function tagged with #[panic_handler]). Those crates can enable this feature to remove the PROVIDE line from the linker script, to stop linking this default panic handler.
See #588 for some info.