Remove #if defined(__CYGWIN__) from complex.h header file

[taneka zenon hans]

Re: GCI 2018 POSIX Compliance test for complex.h file
Without declaring #define __CYGWIN__ 1 , including complex.h itself does not allow the execution of the functions.

The #if defined (__CYGWIN__) wrapping these lines should be removed:

#if defined(__CYGWIN__)
long double complex cacosl(long double complex);
long double complex ccosl(long double complex);
long double complex csinl(long double complex);
long double complex ctanl(long double complex);
long double complex cacoshl(long double complex);
long double complex casinhl(long double complex);
long double complex catanhl(long double complex);
long double complex ccoshl(long double complex);
long double complex csinhl(long double complex);
long double complex ctanhl(long double complex);
long double complex cexpl(long double complex);
long double complex cpowl(long double complex, long double complex);
long double complex conjl(long double complex);
long double complex cprojl(long double complex);

When the bug is fixed, the following files need to have #define __CYGWIN__ 1 removed, along with the corresponding comments referring to this ticket:

In /testsuites/psxtests/psxhdrs/complex/

cacosl.c
ccosl.c
csinl.c
ctanl.c
cacoshl.c
casinhl.c
catanhl.c
ccoshl.c
csinhl.c
ctanhl.c
cexpl.c
cpowl.c
conjl.c
cprojl.c