cmake HAVE_FLOAT examples

JulNadeauCA/libagar CMakeChecks.cmake :476

check_c_source_compiles("
#include <stdio.h>
int
main(int argc, char *argv[])
{
	float f = 0.1f;
	double d = 0.2;

	printf(\"%f\", f);
	return ((double)f + d) > 0.2 ? 1 : 0;
}
" HAVE_FLOAT)