picolibc has redundant declarations of free and strdtold, which results in lots of warnings with -Wredundant-decls. Adjust CFLAGS to remove -Wredundant-decls to make the compiler log more readable.
/usr/lib/picolibc/arm-none-eabi/include/stdlib.h:147:9: warning: redundant redeclaration of 'free' [-Wredundant-decls] 147 | void free (void *) __nothrow; | ^~~~ /usr/lib/picolibc/arm-none-eabi/include/stdlib.h:99:9: note: previous declaration of 'free' with type 'void(void *)' 99 | void free (void *) __nothrow; | ^~~~ /usr/lib/picolibc/arm-none-eabi/include/stdlib.h:307:9: warning: redundant redeclaration of 'strtold' [-Wredundant-decls] 307 | strtold (const char *__restrict, char **__restrict); | ^~~~~~~ /usr/lib/picolibc/arm-none-eabi/include/stdlib.h:286:9: note: previous declaration of 'strtold' with type 'long double(const char * restrict, char ** restrict)' 286 | strtold (const char *__restrict __n, char **__restrict __end_PTR); | ^~~~~~~
