[libsoup] meson: Move HAVE_CONFIG_H define to global args

[Tomas Popela <tpopela src gnome org>]

commit b03ff4e20bd656bc87194db26157b9a9b6c138d3
Author: Jan Alexander Steffens (heftig) <jan steffens gmail com>
Date:   Fri Apr 13 21:27:27 2018 +0200

    meson: Move HAVE_CONFIG_H define to global args
    
    Resolves missing config in examples and tests.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=782410

 libsoup/meson.build |    1 -
 meson.build         |    8 ++++++--
 2 files changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/libsoup/meson.build b/libsoup/meson.build
index 4ead22f..e83bf39 100644
--- a/libsoup/meson.build
+++ b/libsoup/meson.build
@@ -176,7 +176,6 @@ soupenum_h = soup_enums[1]
 soupenum_c = soup_enums[0]
 
 libsoup_c_args  = [
-  '-DHAVE_CONFIG_H',
   '-DG_LOG_DOMAIN="@0@"'.format(meson.project_name()),
   '-DLIBSOUP_COMPILATION'
 ]
diff --git a/meson.build b/meson.build
index 057198e..5a26179 100644
--- a/meson.build
+++ b/meson.build
@@ -20,9 +20,13 @@ libsoup_api_name = '@0@-@1@'.format(meson.project_name(), apiversion)
 
 host_system = host_machine.system()
 
+common_flags = [
+  '-DHAVE_CONFIG_H',
+]
+
 # Enable extra warnings if compiler supports them.
 if cc.get_id() == 'msvc'
-  common_flags = ['/FImsvc_recommended_pragmas.h']
+  common_flags += ['/FImsvc_recommended_pragmas.h']
 else
   test_cflags = [
       '-Wall',
@@ -38,7 +42,7 @@ else
       '-Wno-format-zero-length',
   ]
 
-  common_flags = cc.get_supported_arguments(test_cflags)
+  common_flags += cc.get_supported_arguments(test_cflags)
 endif
 
 add_project_arguments(common_flags, language : 'c')