Provide _M_2_SQRTPI if missing.

	* intrinsics/erfc_scaled.c (_M_2_SQRTPI): Define if missing.

From-SVN: r205731

libgfortran/ChangeLog

+2013-12-06  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
+
+	* intrinsics/erfc_scaled.c (_M_2_SQRTPI): Define if missing.
+
 2013-12-01  Uros Bizjak  <ubizjak@gmail.com>
 
 	PR libfortran/59313

libgfortran/intrinsics/erfc_scaled.c

@@ -61,6 +61,9 @@ see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 #else
 
 # define _THRESH -106.566990228185312813205074546585730L
+# ifndef M_2_SQRTPIl
+#  define M_2_SQRTPIl 1.128379167095512573896158903121545172L
+# endif
 # define _M_2_SQRTPI M_2_SQRTPIl
 # define _INF __builtin_infl()
 # ifdef HAVE_ERFCL