fix unintended global symbols in atanl.c

Mark atanhi, atanlo, and aT in atanl.c as static, as they're not
intended to be part of the public API.

These are already static in the LDBL_MANT_DIG == 64 code, so this
patch is just making the LDBL_MANT_DIG == 113 code do the same thing.

src/math/atanl.c

@@ -70,21 +70,21 @@ static long double T_odd(long double x)
 #elif LDBL_MANT_DIG == 113
 #define EXPMAN(u) ((u.i.se & 0x7fff)<<8 | u.i.top>>8)
 
-const long double atanhi[] = {
+static const long double atanhi[] = {
 	 4.63647609000806116214256231461214397e-01L,
 	 7.85398163397448309615660845819875699e-01L,
 	 9.82793723247329067985710611014666038e-01L,
 	 1.57079632679489661923132169163975140e+00L,
 };
 
-const long double atanlo[] = {
+static const long double atanlo[] = {
 	 4.89509642257333492668618435220297706e-36L,
 	 2.16795253253094525619926100651083806e-35L,
 	-2.31288434538183565909319952098066272e-35L,
 	 4.33590506506189051239852201302167613e-35L,
 };
 
-const long double aT[] = {
+static const long double aT[] = {
 	 3.33333333333333333333333333333333125e-01L,
 	-1.99999999999999999999999999999180430e-01L,
 	 1.42857142857142857142857142125269827e-01L,