printf formatting regression with field width and hh (%02hhx)

The field width (0) and precision (.) options in format specifiers have become broken when used in conjunction with "hh" format at least.

Correct behavior (4.9-2015q2-20150609)
printf("%02hhx", (uint8_t)42) --> 2a
printf("%.2hhx", (uint8_t)42) --> 2a

Faulty behavior (4.9-2015q3-20150921)
printf("%02hhx", (uint8_t)42) --> 0hx
printf("%.2hhx", (uint8_t)42) --> 0hx

Note that "hhx" is also what PRIx8 from <inttypes.h> is defined to.
printf("%02x", (unsigned int)42) is still OK.