There's some problem with busybox 1.25.0-r5, the build fails with error:

```
bootstrap/jdk1.6.0/bin/javac -J-XX:ThreadStackSize=1664 -J-XX:-PrintVMOptions -J-XX:+UnlockDiagnosticVMOptions -J-XX:-LogVMOutput -J-Xmx512m -J-Xms512m -J-XX:PermSize=32m -J-XX:MaxPermSize=160m -g -source 7 -target 7 -encoding ascii -Xbootclasspath:/home/buildozer/aports/community/openjdk7/src/icedtea-2.6.3/openjdk.build-boot/classes -sourcepath /home/buildozer/aports/community/openjdk7/src/icedtea-2.6.3/generated.build:../../../src/solaris/classes:../../../src/share/classes -d /home/buildozer/aports/community/openjdk7/src/icedtea-2.6.3/openjdk.build-boot/classes @/home/buildozer/aports/community/openjdk7/src/icedtea-2.6.3/openjdk.build-boot/tmp/sun/sun.awt.X11/xawt/.classes.list.filtered
Annotation processing got disabled, since it requires a 1.6 compliant JVM
----------
1. ERROR in /home/buildozer/aports/community/openjdk7/src/icedtea-2.6.3/openjdk-boot/jdk/src/solaris/classes/sun/awt/X11/XWarningWindow.java (at line 64)
    icons[0][0] = new IconInfo(sun.awt.AWTIcon32_security_icon_bw16_png.security_icon_bw16_png);
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
sun.awt.AWTIcon32_security_icon_bw16_png cannot be resolved to a variable
----------
2. ERROR in /home/buildozer/aports/community/openjdk7/src/icedtea-2.6.3/openjdk-boot/jdk/src/solaris/classes/sun/awt/X11/XWarningWindow.java (at line 65)
    icons[0][1] = new IconInfo(sun.awt.AWTIcon32_security_icon_interim16_png.security_icon_interim16_png);
                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
sun.awt.AWTIcon32_security_icon_interim16_png cannot be resolved to a variable
----------
...
32. ERROR in /home/buildozer/aports/community/openjdk7/src/icedtea-2.6.3/openjdk-boot/jdk/src/solaris/classes/sun/awt/X11/XWindowPeer.java (at line 438)
    defaultIconInfo.add(new IconInfo(sun.awt.AWTIcon64_java_icon48_png.java_icon48_png));
                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
sun.awt.AWTIcon64_java_icon48_png cannot be resolved to a variable
----------
```

This means that files AWTIcon*.java are missing, they haven't been
generated for some unknown reason.

I verified that the build works on edge with busybox 1.24.2-r11 (from v3.4).

The fix involves installing coreutils, so it's more a workaround, but
IcedTea's build system is very complex, so finding the root cause would be
very difficult and time consuming.

Note: Installing just GNU sed didn't help.