dependencies: Reject gcj in BR2_NEEDS_HOST_JAVA check

Xbmc uses the Groovy java package to generate API code, for details see
http://wiki.xbmc.org/index.php?title=Codegeneration#How_it_works

Groovy itself is broken when used with gcj:
http://jira.codehaus.org/browse/GROOVY-3701

Xbmc recommends to use another java package instead, like openjdk:
http://forum.xbmc.org/showthread.php?tid=199742

Until we come up with a host package to provide a java setup and
in order to make autobuilder happy let´s reject gcj when we check
for a java installation on the host.

Currently Xbmc is the only package using BR2_NEEDS_HOST_JAVA
so changing the behaviour of dependencies.sh has no side effects.

Fixes
http://autobuild.buildroot.net/results/213/213d7454a1dc68cfb8f4c8d9508f52ebf8e58e33/
http://autobuild.buildroot.net/results/639/639cda872cf36c122cbd6139dd76f6b51ac1864e/
http://autobuild.buildroot.net/results/c9e/c9eb12c95b2939c64590692a82af8d84bbd90956/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

support/dependencies/dependencies.sh

@@ -189,6 +189,13 @@ fi
 
 if grep -q ^BR2_NEEDS_HOST_JAVA=y $BR2_CONFIG ; then
 	check_prog_host "java"
+	JAVA_GCJ=$(java -version 2>&1 | grep gcj)
+	if [ ! -z "$JAVA_GCJ" ] ; then
+		echo
+		echo "$JAVA_GCJ is not sufficient to compile your package selection."
+		echo "Please install an OpenJDK/IcedTea/Oracle Java."
+		exit 1 ;
+	fi
 fi
 
 if grep -q ^BR2_NEEDS_HOST_JAVAC=y $BR2_CONFIG ; then