FIRST_STRING_P    936 regex.cpp            if (FIRST_STRING_P (where))
FIRST_STRING_P   3567 regex.cpp        (FIRST_STRING_P (ptr)				\
FIRST_STRING_P   3961 regex.cpp      	      same_str_p = (FIRST_STRING_P (match_end)
FIRST_STRING_P   4411 regex.cpp                  dend2 = ((FIRST_STRING_P (regstart[regno])
FIRST_STRING_P   4412 regex.cpp      		      == FIRST_STRING_P (regend[regno]))