[gtk-vnc] Ignore cast align warnings to avoid tripping up clang

[Daniel P. Berrange <dberrange src gnome org>]

commit ceaeee79fab707513305796202cb1c5c46bce715
Author: Daniel P. Berrange <berrange redhat com>
Date:   Tue Aug 16 11:03:37 2016 +0100

    Ignore cast align warnings to avoid tripping up clang
    
    Resolves: bz#765389
    Signed-off-by: Daniel P. Berrange <berrange redhat com>

 m4/gtk-vnc-warnings.m4 |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/m4/gtk-vnc-warnings.m4 b/m4/gtk-vnc-warnings.m4
index 29cfb51..c2334d0 100644
--- a/m4/gtk-vnc-warnings.m4
+++ b/m4/gtk-vnc-warnings.m4
@@ -49,6 +49,8 @@ AC_DEFUN([GTK_VNC_COMPILE_WARNINGS],[
     dontwarn="$dontwarn -Wbad-function-cast"
     # Broken code in glib2's gparam.h
     dontwarn="$dontwarn -Wshift-overflow=2"
+    # CLang trips up on this see bz #765389
+    dontwarn="$dontwarn -Wcast-align"
     # Get all possible GCC warnings
     gl_MANYWARN_ALL_GCC([maybewarn])