Building tests requires C99, can `-std=c99` be passed when tests are enabled?

[barracuda156]

This is with gcc-4.2:

../bstring-1.0.1/tests/bstest.c: In function ‘core_043_fn’:
../bstring-1.0.1/tests/bstest.c:2758: error: ‘for’ loop initial declaration used outside C99 mode
../bstring-1.0.1/tests/bstest.c:2764: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2764: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2766: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2766: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2770: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2770: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2772: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2772: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2776: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2776: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2778: warning: ISO C90 does not support the ‘j’ printf length modifier
../bstring-1.0.1/tests/bstest.c:2778: warning: ISO C90 does not support the ‘j’ printf length modifier

There is no error if -std=c99 is passed to cflags, the build succeeds then.