Patch pkg-config and update installs for various packages

var/spack/repos/builtin/packages/pkg-config/g_date_strftime.patch

@@ -0,0 +1,33 @@
+From 00148329967adb196138372771052a3f606a6ea3 Mon Sep 17 00:00:00 2001
+From: coypu <coypu@sdf.org>
+Date: Wed, 2 Mar 2016 19:43:10 +0200
+Subject: [PATCH 2/2] gdate: Suppress string format literal warning
+
+Newer versions of GCC emit an error here, but we know it's safe.
+https://bugzilla.gnome.org/761550
+---
+ glib/glib/gdate.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/glib/glib/gdate.c b/glib/glib/gdate.c
+index 4aece02..92c34d2 100644
+--- a/glib/glib/gdate.c
++++ b/glib/glib/gdate.c
+@@ -2439,6 +2439,9 @@ win32_strftime_helper (const GDate     *d,
+  *
+  * Returns: number of characters written to the buffer, or 0 the buffer was too small
+  */
++#pragma GCC diagnostic push
++#pragma GCC diagnostic ignored "-Wformat-nonliteral"
++
+ gsize
+ g_date_strftime (gchar       *s,
+                  gsize        slen,
+@@ -2549,3 +2552,5 @@ g_date_strftime (gchar       *s,
+   return retval;
+ #endif
+ }
++
++#pragma GCC diagnostic pop
+--
+2.7.1

var/spack/repos/builtin/packages/pkg-config/package.py

@@ -37,6 +37,9 @@ class PkgConfig(Package):
 
     parallel = False
 
+    # The following patch is needed for gcc-6.1
+    patch('g_date_strftime.patch')
+
     def install(self, spec, prefix):
         configure("--prefix={0}".format(prefix),
                   "--enable-shared",