[vte] build: Use AC_USE_SYSTEM_EXTENSIONS

[Christian Persch <chpe src gnome org>]

commit f97eb914b0776644931dbb571779c3a99572598f
Author: Christian Persch <chpe gnome org>
Date:   Wed Apr 23 19:21:06 2014 +0200

    build: Use AC_USE_SYSTEM_EXTENSIONS
    
    ... instead of some grep magic.

 configure.ac |   20 +-------------------
 1 files changed, 1 insertions(+), 19 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index a28abe2..dedff4d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -54,6 +54,7 @@ AC_SUBST([GTK_API_VERSION])
 
 # Check for programs
 AC_PROG_CC
+AC_USE_SYSTEM_EXTENSIONS
 AC_HEADER_STDC
 AM_PROG_CC_C_O
 AC_PROG_SED
@@ -169,25 +170,6 @@ AC_SUBST([VTE_LDFLAGS])
 # Core
 ################################################################################
 
-# Use all available features under glibc, and disable accidental use of
-# deprecated functionality.
-AC_EGREP_CPP(glibc,
-               [
-                #include <stdio.h>
-                #ifdef __GLIBC__
-                glibc
-                #endif
-               ],
-               AC_DEFINE(_GNU_SOURCE,1,[Use all glibc features.]))
-
-case $host in
-*-*-solaris*)
-       AC_DEFINE(_XOPEN_SOURCE_EXTENDED,1,[Needed to get declarations for msg_control and msg_controllen on 
Solaris])
-       AC_DEFINE(_XOPEN_SOURCE,1,[Needed to get declarations for msg_control and msg_controllen on Solaris])
-       AC_DEFINE(__EXTENSIONS__,1,[Needed to get declarations for msg_control and msg_controllen on Solaris])
-       ;;
-esac
-
 GLIB_REQUIRED=2.40.0
 GIO_REQUIRED=2.40.0
 PANGO_REQUIRED=1.22.0