gcc5: Upgrade to gcc 5.4

Drop patches which has been applied to gcc5 branch
until 5.4 release

(From OE-Core rev: 42487843f846ae61f8bd1b2278d148ff37f0d667)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-devtools/gcc/gcc-5.4/0025-libtool.patch

@@ -0,0 +1,42 @@
+From f68c5b78751660505b22b46dad99240db0df3456 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Fri, 29 Mar 2013 09:29:11 +0400
+Subject: [PATCH 25/46] libtool
+
+libstdc++ from gcc-runtime gets created with -rpath=/usr/lib/../lib for qemux86-64
+when running on am x86_64 build host.
+
+This patch stops this speading to libdir in the libstdc++.la file within libtool.
+Arguably, it shouldn't be passing this into libtool in the first place but
+for now this resolves the nastiest problems this causes.
+
+func_normal_abspath would resolve an empty path to `pwd` so we need
+to filter the zero case.
+
+RP 2012/8/24
+
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+
+Upstream-Status: Pending
+---
+ ltmain.sh | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/ltmain.sh b/ltmain.sh
+index 9503ec8..0121fba 100644
+--- a/ltmain.sh
++++ b/ltmain.sh
+@@ -6359,6 +6359,10 @@ func_mode_link ()
+ 	func_warning "ignoring multiple \`-rpath's for a libtool library"
+ 
+       install_libdir="$1"
++      if test -n "$install_libdir"; then
++	func_normal_abspath "$install_libdir"
++	install_libdir=$func_normal_abspath_result
++      fi
+ 
+       oldlibs=
+       if test -z "$rpath"; then
+-- 
+2.6.3
+