libffi: refresh patches

The patch tool will apply patches by default with "fuzz", which is where if the
hunk context isn't present but what is there is close enough, it will force the
patch in.

Whilst this is useful when there's just whitespace changes, when applied to
source it is possible for a patch applied with fuzz to produce broken code which
still compiles (see #10450).  This is obviously bad.

We'd like to eventually have do_patch() rejecting any fuzz on these grounds. For
that to be realistic the existing patches with fuzz need to be rebased and
reviewed.

(From OE-Core rev: 7ae4ce08071c02beaf09675c2c1ed70617b797dd)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Alexander Kanavin <alexander.kanavin@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-support/libffi/libffi/not-win32.patch

@@ -11,12 +11,16 @@ As this block is generally pointless, disable it.
 Upstream-Status: Inappropriate
 Signed-off-by: Ross Burton <ross.burton@intel.com>
 
---- a/configure.ac~	2014-11-12 11:56:51.000000000 +0000
-+++ b/configure.ac	2016-02-04 14:02:53.765710532 +0000
-@@ -593,5 +593,5 @@
+Index: libffi-3.2.1/configure.ac
+===================================================================
+--- libffi-3.2.1.orig/configure.ac
++++ libffi-3.2.1/configure.ac
+@@ -592,7 +592,7 @@ AC_ARG_ENABLE(purify-safety,
+ 
  # These variables are only ever used when we cross-build to X86_WIN32.
  # And we only support this with GCC, so...
 -if test "x$GCC" = "xyes"; then
 +if false; then
    if test -n "$with_cross_host" &&
-      test x"$with_cross_host" != x"no"; then
+      test x"$with_cross_host" != x"no"; then
+     toolexecdir="${exec_prefix}"/'$(target_alias)'