add required linker flags.

--- openjdk-6.orig/jdk/make/java/instrument/Makefile	2011-02-28 17:06:10.000000000 +0100
+++ openjdk-6/jdk/make/java/instrument/Makefile	2011-04-11 23:14:27.571411016 +0200
@@ -123,6 +123,8 @@
 # We don't want to link against -ljava
 JAVALIB=
 
+LDLIBS += -liconv
+
 #
 # Add to ambient vpath so we pick up the library files
 #
--- openjdk-6.orig/jdk/make/java/npt/Makefile	2011-02-28 17:06:11.000000000 +0100
+++ openjdk-6/jdk/make/java/npt/Makefile	2011-04-11 23:14:07.017670197 +0200
@@ -65,6 +65,8 @@
 # We don't want to link against -ljava
 JAVALIB=
 
+LDLIBS += -liconv
+
 # Add -export options to explicitly spell exported symbols
 ifeq ($(PLATFORM), windows)
   OTHER_LCF += -export:nptInitialize -export:nptTerminate
--- openjdk-6.orig/jdk/make/sun/splashscreen/Makefile	2011-02-28 17:06:12.000000000 +0100
+++ openjdk-6/jdk/make/sun/splashscreen/Makefile	2011-04-11 23:15:07.221411030 +0200
@@ -55,6 +55,8 @@
 
 JAVALIB=
 
+LDLIBS += -liconv
+
 #
 # C Flags
 #