[vala/staging] glib-2.0: add feature test macro _GNU_SOURCE for exp10(3) and exp10f(3)

[Dr. Michael Lauer <mlauer src gnome org>]

commit 2c9e89d0a771ed42d46a28cffbf047790714c216
Author: Dr. Michael Lauer <mickey vanille-media de>
Date:   Mon Feb 26 17:11:39 2018 +0100

    glib-2.0: add feature test macro _GNU_SOURCE for exp10(3) and exp10f(3)

 vapi/glib-2.0.vapi |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/vapi/glib-2.0.vapi b/vapi/glib-2.0.vapi
index 56f847e..8278574 100644
--- a/vapi/glib-2.0.vapi
+++ b/vapi/glib-2.0.vapi
@@ -1573,7 +1573,9 @@ namespace GLib {
                public static float log10f (float x);
                public static double modf (double x, out double iptr);
                public static float modff (float x, out float iptr);
+               [CCode (feature_test_macro = "_GNU_SOURCE")]
                public static double exp10 (double x);
+               [CCode (feature_test_macro = "_GNU_SOURCE")]
                public static float exp10f (float x);
                [CCode (feature_test_macro = "_GNU_SOURCE")]
                public static double pow10 (double x);