In lwip-2.1.3 tcp_output_control_segment() is used to send RST, empty
ACK, keepalive or zero window probe.
In lwip-2.2.0 this works the same, but the function is used when we
don't know the interface to send to (and if used it finds it and calls)
tcp_output_control_segment_netif().
When `LWIP_EXTRA_IRAM_OPTIMIZATION=y` we would ideally move both
variants to IRAM, but the pcb variant (tcp_output_control_segment) could
be optimized away on some targets and toolchain versions.
(esp32c6 with riscv32-esp-elf/esp-14.2.0_20240906)
It should be sufficient to keep tcp_output_control_segment_netif in IRAM
for most common performance usecases.
Fix dependency tree so that lwip doesn't depend on any specific network
interface component.
Network interface drivers shall depend on esp_netif.
esp_netif shall depend on lwip (but not on any specific interface
driver) -- it optionally depends on vfs and esp_eth (need ethernet
header for L2/bridge mode)
Include external ram section in the linker template to process it
through linker script generation mechanism. This enables redirection of .bss section to external memory using linker fragments
libnet80211, libpp, libbt, liblwip: Redirect .bss through fragments
