remove long double const workarounds

Some long double consts were stored in two doubles as a workaround
for x86_64 and i386 with the following comment:
/* Long double constants are slow on these arches, and broken on i386. */
This is most likely old gcc bug related to the default x87 fpu
precision setting (it's double instead of double extended on BSD).

src/math/atan2l.c

@@ -27,16 +27,8 @@ long double atan2l(long double y, long double x)
 static const volatile long double
 tiny = 1.0e-300;
 static const long double
-zero = 0.0;
-/* XXX Work around the fact that gcc truncates long double constants on i386 */
-static const volatile double
-pi1 = 3.14159265358979311600e+00, /* 0x1.921fb54442d18p+1  */
-pi2 = 1.22514845490862001043e-16; /* 0x1.1a80000000000p-53 */
-#define pi ((long double)pi1 + pi2)
-#if 0
-static const long double
+zero = 0.0,
 pi = 3.14159265358979323846264338327950280e+00L;
-#endif
 
 long double atan2l(long double y, long double x)
 {