/opt/IBM/openxlC/17.1.1/bin/ibm-clang -pthread  -Wall -Wextra -Werror=implicit-function-declaration stdlib/reallocarray.c -o stdlib/reallocarray -D_GNU_SOURCE -D_BSD_SOURCE -D_ALL_SOURCE -D_DEFAULT_SOURCE -lm -lpthread -lrt -latomic
stdlib/reallocarray.c:16:12: error: call to undeclared function 'reallocarray'; ISO C99 and later do not support implicit function declarations [-Werror,-Wimplicit-function-declaration]
        numbers = reallocarray(numbers, 16, sizeof(int));
                  ^
stdlib/reallocarray.c:16:10: warning: incompatible integer to pointer conversion assigning to 'int *' from 'int' [-Wint-conversion]
        numbers = reallocarray(numbers, 16, sizeof(int));
                ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 warning and 1 error generated.