_PFLINK is supposed to automatically pull in required functions for
specific conversion specifiers. However, it fails to do so for the F,
G and E conversion specifiers.
This means that, for example, the following program:
#include <stdio.h>
int main()
{
printf("%F %G %E\n", .0, .0, .0);
}
fails to run correctly, printing "? ? ?" instead of
"0.000000 0 0.000000E+00".
This patch fixes this.