[gnome-builder] meson: ignore _build directory

[Christian Hergert <chergert src gnome org>]

commit fb6e706ccaceb650933b20ac5cccdd6da814ee2e
Author: Christian Hergert <chergert redhat com>
Date:   Wed Jan 16 15:30:01 2019 -0800

    meson: ignore _build directory
    
    We use this for our internal build directory, so we want to make sure that
    we don't follow it.

 src/plugins/meson/meson-plugin.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/plugins/meson/meson-plugin.c b/src/plugins/meson/meson-plugin.c
index cea513d08..b58e8d0d3 100644
--- a/src/plugins/meson/meson-plugin.c
+++ b/src/plugins/meson/meson-plugin.c
@@ -33,6 +33,9 @@
 _IDE_EXTERN void
 _gbp_meson_register_types (PeasObjectModule *module)
 {
+  /* For in-tree builds of meson projects */
+  ide_g_file_add_ignored_pattern ("_build");
+
   peas_object_module_register_extension_type (module,
                                               IDE_TYPE_PIPELINE_ADDIN,
                                               GBP_TYPE_MESON_PIPELINE_ADDIN);