built-in function ‘y1’ declared as non-function

[fhaverkamp]

Ony my system y1 seems to be used already:

/home/haver/HTX//export/ppc64le//include/expirekey.h:94:5: warning: built-in function ‘y1’ declared as non-function
int y1 = 4 ;

Y0(3) Linux Programmer's Manual Y0(3)

NAME
y0, y0f, y0l, y1, y1f, y1l, yn, ynf, ynl - Bessel functions of the second kind

SYNOPSIS
#include <math.h>

   double y0(double x);
   double y1(double x);
   double yn(int n, double x);

   float y0f(float x);
   float y1f(float x);
   float ynf(int n, float x);

   long double y0l(long double x);
   long double y1l(long double x);
   long double ynl(int n, long double x);

   Link with -lm.

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

[asukaminato0721]

because y1 is a built-in function in mingw, use y2/y3...etc instead.