Original patch from gentoo: gentoo/src/patchsets/gcc/4.3.1/gentoo/03_all_gcc43-java-nomulti.patch
diff -durN gcc-4.3.1.orig/libjava/configure gcc-4.3.1/libjava/configure
--- gcc-4.3.1.orig/libjava/configure	2008-06-06 16:49:11.000000000 +0200
+++ gcc-4.3.1/libjava/configure	2008-06-10 14:57:38.000000000 +0200
@@ -1018,6 +1018,8 @@
   --enable-gconf-peer     compile GConf native peers for util.preferences
   --enable-java-maintainer-mode
                           allow rebuilding of .class and .h files
+  --enable-libjava-multilib
+                          build libjava as multilib
   --disable-dependency-tracking  speeds up one-time build
   --enable-dependency-tracking   do not reject slow dependency extractors
   --enable-maintainer-mode  enable make rules and dependencies not useful
@@ -1850,6 +1852,16 @@
 fi
 
 
+# Check whether --enable-libjava-multilib was given.
+if test "${enable_libjava_multilib+set}" = set; then
+  enableval=$enable_libjava_multilib;
+fi
+
+if test "$enable_libjava_multilib" = no; then
+  multilib=no
+  ac_configure_args="$ac_configure_args --disable-multilib"
+fi
+
 # It may not be safe to run linking tests in AC_PROG_CC/AC_PROG_CXX.
 
 
diff -durN gcc-4.3.1.orig/libjava/configure.ac gcc-4.3.1/libjava/configure.ac
--- gcc-4.3.1.orig/libjava/configure.ac	2007-12-22 16:48:46.000000000 +0100
+++ gcc-4.3.1/libjava/configure.ac	2008-06-10 14:57:38.000000000 +0200
@@ -82,6 +82,13 @@
 	[allow rebuilding of .class and .h files]))
 AM_CONDITIONAL(JAVA_MAINTAINER_MODE, test "$enable_java_maintainer_mode" = yes)
 
+AC_ARG_ENABLE(libjava-multilib,
+	AS_HELP_STRING([--enable-libjava-multilib], [build libjava as multilib]))
+if test "$enable_libjava_multilib" = no; then
+  multilib=no
+  ac_configure_args="$ac_configure_args --disable-multilib"
+fi
+
 # It may not be safe to run linking tests in AC_PROG_CC/AC_PROG_CXX.
 GCC_NO_EXECUTABLES