[gnome-builder] meson-templates: set C/C++ standard in project()

[Christian Hergert <chergert src gnome org>]

commit e27458dbeab4d1e394c5d14ee5ca3df04784b710
Author: Christian Hergert <chergert redhat com>
Date:   Wed Apr 24 15:14:02 2019 -0700

    meson-templates: set C/C++ standard in project()

 src/plugins/meson-templates/resources/meson.build | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/meson-templates/resources/meson.build 
b/src/plugins/meson-templates/resources/meson.build
index 275cde5df..75120c039 100644
--- a/src/plugins/meson-templates/resources/meson.build
+++ b/src/plugins/meson-templates/resources/meson.build
@@ -1,6 +1,14 @@
 project('{{name}}', {{if language == "c"}}'c',{{else if language == "c++"}}['cpp', 'c'],{{else if language 
== "vala"}}['c', 'vala'],{{else if language == "c♯"}}'cs',{{end}}
-        version: '{{project_version}}',
-  meson_version: '>= 0.40.0',
+          version: '{{project_version}}',
+    meson_version: '>= 0.49.0',
+  default_options: [ 'warning_level=2',
+{{if language == "c"}}
+                     'c_std=gnu11',
+{{end}}
+{{if language == "c++"}}
+                     'cpp_std=gnu++2a',
+{{end}}
+                   ],
 )
 
 {{if enable_i18n}}