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.
Aguably, 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

Upstream-Status: Pending

Index: git/ltmain.sh
===================================================================
--- git.orig/ltmain.sh	2012-08-24 11:45:58.597087961 +0000
+++ git/ltmain.sh	2012-08-24 12:18:37.961042581 +0000
@@ -6359,6 +6359,10 @@
 	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