implicit-function-declaration becomes a hard error under -std=c11 with -Werror in GCC
A shared C library is being integrated with a newer GCC toolchain, and the build must decide whether calls without prior prototypes should fail compilation or remain warnings. The codebase was originally compiled with gnu89 defaults, where implicit function declaration is permitted silently, but the target pipeline uses -std=c11 with -Werror=implicit-functio