[scripts] Add bleeding edge OpenJDK support

Author: JakubVanek

README.md

@@ -37,6 +37,7 @@ Please change the `$BUILD_DIRECTORY` to a valid path.
 ```
 export JDKVER=9      # OpenJDK 9
 export JDKVER=10     # OpenJDK 10
+export JDKVER=dev    # OpenJDK Master+dev (to-be OpenJDK 11 at the time of writing)
 export JDKVM=zero    # Use Zero interpreter
 export JDKVM=client  # Use ARM32 JIT
 ```

scripts/config.sh

@@ -64,12 +64,23 @@ elif [ "$JDKVER" == "10" ]; then
   HOSTJDK_FILE="$BUILDDIR/openjdk-10_linux-x64_bin.tar.gz"
   HOSTJDK_URL="https://download.java.net/java/GA/jdk10/10/binaries/openjdk-10_linux-x64_bin.tar.gz"
 
+# OpenJDK Master+dev
+elif [ "$JDKVER" == "dev" ]; then
+  JAVA_REPO="http://hg.openjdk.java.net/jdk/jdk/"
+  PATCHVER="jdkdev"
+  AUTOGEN_PATH="./make/autoconf/autogen.sh"
+  HOSTJDK="$BUILDDIR/jdk-10"
+  HOSTJDK_FILE="$BUILDDIR/openjdk-10_linux-x64_bin.tar.gz"
+  HOSTJDK_URL="https://download.java.net/java/GA/jdk10/10/binaries/openjdk-10_linux-x64_bin.tar.gz"
+
+
 # invalid or unset version
 else
   echo "Error! Please specify JDK version to compile via the JDKVER environment variable." >&2
   echo "Acceptable values:" >&2
   echo "JDKVER=9" >&2
   echo "JDKVER=10" >&2
+  echo "JDKVER=dev" >&2
   exit 1
 fi