[CUDA][Windows] restrict long double device functions declarations to Windows

[emankov]

Summary

As agreed in D60220, make long double declarations unobservable on non-windows platforms.

[tra]

LGTM. Thank you for cleaning this up.

lib/Headers/__clang_cuda_cmath.h

__DEVICE__ float frexp(float __arg, int *__exp) {
   return ::frexpf(__arg, __exp);
 }
 
 // For inscrutable reasons, the CUDA headers define these functions for us on
 // Windows.
 #ifndef _MSC_VER
 __DEVICE__ bool isinf(float __x) { return ::__isinff(__x); }
 __DEVICE__ bool isinf(double __x) { return ::__isinf(__x); }
-__DEVICE__ bool isinf(long double __x) { return ::__isinfl(__x); }
 __DEVICE__ bool isfinite(float __x) { return ::__finitef(__x); }
 // For inscrutable reasons, __finite(), the double-precision version of
 // __finitef, does not exist when compiling for MacOS.  __isfinited is available
 // everywhere and is just as good.
 __DEVICE__ bool isfinite(double __x) { return ::__isfinited(__x); }
-__DEVICE__ bool isfinite(long double __x) { return ::__finitel(__x); }
 __DEVICE__ bool isnan(float __x) { return ::__isnanf(__x); }
 __DEVICE__ bool isnan(double __x) { return ::__isnan(__x); }
-__DEVICE__ bool isnan(long double __x) { return ::__isnanl(__x); }
 #endif
 
 __DEVICE__ bool isgreater(float __x, float __y) {
   return __builtin_isgreater(__x, __y);
 }
 __DEVICE__ bool isgreater(double __x, double __y) {
   return __builtin_isgreater(__x, __y);
 }

lib/Headers/__clang_cuda_device_functions.h

 }
 __DEVICE__ float __fdividef(float __a, float __b) {
   return __nv_fast_fdividef(__a, __b);
 }
 __DEVICE__ int __ffs(int __a) { return __nv_ffs(__a); }
 __DEVICE__ int __ffsll(long long __a) { return __nv_ffsll(__a); }
 __DEVICE__ int __finite(double __a) { return __nv_isfinited(__a); }
 __DEVICE__ int __finitef(float __a) { return __nv_finitef(__a); }
+#ifdef _MSC_VER
 __DEVICE__ int __finitel(long double __a);
+#endif
 __DEVICE__ int __float2int_rd(float __a) { return __nv_float2int_rd(__a); }
 __DEVICE__ int __float2int_rn(float __a) { return __nv_float2int_rn(__a); }
 __DEVICE__ int __float2int_ru(float __a) { return __nv_float2int_ru(__a); }
 __DEVICE__ int __float2int_rz(float __a) { return __nv_float2int_rz(__a); }
 __DEVICE__ long long __float2ll_rd(float __a) { return __nv_float2ll_rd(__a); }
 __DEVICE__ long long __float2ll_rn(float __a) { return __nv_float2ll_rn(__a); }
 __DEVICE__ long long __float2ll_ru(float __a) { return __nv_float2ll_ru(__a); }
 __DEVICE__ long long __float2ll_rz(float __a) { return __nv_float2ll_rz(__a); }

 __DEVICE__ float __int2float_rd(int __a) { return __nv_int2float_rd(__a); }
 __DEVICE__ float __int2float_rn(int __a) { return __nv_int2float_rn(__a); }
 __DEVICE__ float __int2float_ru(int __a) { return __nv_int2float_ru(__a); }
 __DEVICE__ float __int2float_rz(int __a) { return __nv_int2float_rz(__a); }
 __DEVICE__ float __int_as_float(int __a) { return __nv_int_as_float(__a); }
 __DEVICE__ int __isfinited(double __a) { return __nv_isfinited(__a); }
 __DEVICE__ int __isinf(double __a) { return __nv_isinfd(__a); }
 __DEVICE__ int __isinff(float __a) { return __nv_isinff(__a); }
+#ifdef _MSC_VER
 __DEVICE__ int __isinfl(long double __a);
+#endif
 __DEVICE__ int __isnan(double __a) { return __nv_isnand(__a); }
 __DEVICE__ int __isnanf(float __a) { return __nv_isnanf(__a); }
+#ifdef _MSC_VER
 __DEVICE__ int __isnanl(long double __a);
+#endif
 __DEVICE__ double __ll2double_rd(long long __a) {
   return __nv_ll2double_rd(__a);
 }
 __DEVICE__ double __ll2double_rn(long long __a) {
   return __nv_ll2double_rn(__a);
 }
 __DEVICE__ double __ll2double_ru(long long __a) {
   return __nv_ll2double_ru(__a);

lib/Headers/__clang_cuda_math_forward_declares.h

 __DEVICE__ int fpclassify(double);
 __DEVICE__ int fpclassify(float);
 __DEVICE__ double frexp(double, int *);
 __DEVICE__ float frexp(float, int *);
 __DEVICE__ double hypot(double, double);
 __DEVICE__ float hypot(float, float);
 __DEVICE__ int ilogb(double);
 __DEVICE__ int ilogb(float);
+#ifdef _MSC_VER
 __DEVICE__ bool isfinite(long double);
+#endif
 __DEVICE__ bool isfinite(double);
 __DEVICE__ bool isfinite(float);
 __DEVICE__ bool isgreater(double, double);
 __DEVICE__ bool isgreaterequal(double, double);
 __DEVICE__ bool isgreaterequal(float, float);
 __DEVICE__ bool isgreater(float, float);
+#ifdef _MSC_VER
 __DEVICE__ bool isinf(long double);
+#endif
 __DEVICE__ bool isinf(double);
 __DEVICE__ bool isinf(float);
 __DEVICE__ bool isless(double, double);
 __DEVICE__ bool islessequal(double, double);
 __DEVICE__ bool islessequal(float, float);
 __DEVICE__ bool isless(float, float);
 __DEVICE__ bool islessgreater(double, double);
 __DEVICE__ bool islessgreater(float, float);
+#ifdef _MSC_VER
 __DEVICE__ bool isnan(long double);
+#endif
 __DEVICE__ bool isnan(double);
 __DEVICE__ bool isnan(float);
 __DEVICE__ bool isnormal(double);
 __DEVICE__ bool isnormal(float);
 __DEVICE__ bool isunordered(double, double);
 __DEVICE__ bool isunordered(float, float);
 __DEVICE__ long labs(long);
 __DEVICE__ double ldexp(double, int);