Improve header test for C++

This patch ensures that we don't miss G_BEGIN_DECLS/G_END_DECLS on
any public header.

Signed-off-by: Stephen Gallagher <sgallagh@redhat.com>

Author: sgallagher

modulemd/common/tests/test-import-headers.sh

@@ -40,6 +40,17 @@ EOF
       -I `dirname $arg` \
       -o $header.out \
       $header.c
+
+  echo "g++ \`pkg-config --cflags gobject-2.0\` \
+            \`pkg-config --cflags yaml-0.1\` \
+            -I `dirname $arg` \
+            -o $header.out \
+            $header.c"
+  g++ `pkg-config --cflags gobject-2.0` \
+      `pkg-config --cflags yaml-0.1` \
+      -I `dirname $arg` \
+      -o $header.out \
+      $header.c
 done
 
 popd

modulemd/v2/include/modulemd-2.0/modulemd-buildopts.h

@@ -112,3 +112,5 @@ modulemd_buildopts_remove_rpm_from_whitelist (ModulemdBuildopts *self,
  */
 gchar **
 modulemd_buildopts_get_rpm_whitelist_as_strv (ModulemdBuildopts *self);
+
+G_END_DECLS

modulemd/v2/include/modulemd-2.0/modulemd-component-module.h

@@ -91,3 +91,5 @@ modulemd_component_module_set_repository (ModulemdComponentModule *self,
  */
 const gchar *
 modulemd_component_module_get_repository (ModulemdComponentModule *self);
+
+G_END_DECLS

modulemd/v2/include/modulemd-2.0/modulemd-component-rpm.h

@@ -191,3 +191,5 @@ modulemd_component_rpm_set_repository (ModulemdComponentRpm *self,
  */
 const gchar *
 modulemd_component_rpm_get_repository (ModulemdComponentRpm *self);
+
+G_END_DECLS

modulemd/v2/include/modulemd-2.0/modulemd-component.h

@@ -109,3 +109,5 @@ modulemd_component_set_rationale (ModulemdComponent *self,
  */
 const gchar *
 modulemd_component_get_rationale (ModulemdComponent *self);
+
+G_END_DECLS

modulemd/v2/include/modulemd-2.0/modulemd-dependencies.h

@@ -165,3 +165,5 @@ modulemd_dependencies_get_runtime_modules_as_strv (ModulemdDependencies *self);
 GStrv
 modulemd_dependencies_get_runtime_streams_as_strv (ModulemdDependencies *self,
                                                    const gchar *module);
+
+G_END_DECLS

modulemd/v2/include/modulemd-2.0/modulemd-deprecated.h

@@ -13,6 +13,10 @@
 
 #pragma once
 
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
 #ifdef MMD_DISABLE_DEPRECATION_WARNINGS
 #define MMD_DEPRECATED extern
 #define MMD_DEPRECATED_FOR(f) extern
@@ -24,3 +28,5 @@
 #define MMD_DEPRECATED_TYPE_FOR(f) G_DEPRECATED_FOR (f)
 #define MMD_UNAVAILABLE(maj, min) G_UNAVAILABLE (maj, min) extern
 #endif
+
+G_END_DECLS

modulemd/v2/include/modulemd-2.0/modulemd-module.h

@@ -127,3 +127,5 @@ modulemd_module_get_stream_by_NSVC (ModulemdModule *self,
  */
 ModulemdDefaults *
 modulemd_module_get_defaults (ModulemdModule *self);
+
+G_END_DECLS

modulemd/v2/include/modulemd-2.0/modulemd-profile.h

@@ -132,3 +132,5 @@ modulemd_profile_remove_rpm (ModulemdProfile *self, const gchar *rpm);
  */
 gchar **
 modulemd_profile_get_rpms_as_strv (ModulemdProfile *self);
+
+G_END_DECLS

modulemd/v2/include/modulemd-2.0/modulemd-subdocument-info.h

@@ -55,3 +55,5 @@ modulemd_subdocument_info_get_yaml (ModulemdSubdocumentInfo *self);
  */
 const GError *
 modulemd_subdocument_info_get_gerror (ModulemdSubdocumentInfo *self);
+
+G_END_DECLS