Gradle: Support Java 11 Version Name

[jpe42]

Gradle fails to recognize the version name "11-ea".

Expected Behavior

Gradle runs against Java 11 early access releases.

Current Behavior

➜ git:(master) java -version
java version "11-ea" 2018-09-18
Java(TM) SE Runtime Environment 18.9 (build 11-ea+2)
Java HotSpot(TM) 64-Bit Server VM 18.9 (build 11-ea+2, mixed mode)

➜ git:(master) ./gradlew -version

FAILURE: Build failed with an exception.

* What went wrong:
Could not determine java version from '11-ea'.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

➜ git:(master) jenv shell 10-ea
➜ git:(master) java -version
java version "10" 2018-03-20
Java(TM) SE Runtime Environment 18.3 (build 10+44)
Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10+44, mixed mode)

➜ git:(master) ./gradlew -version
WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.codehaus.groovy.reflection.CachedClass (file:/Users/jamesedwards/.gradle/wrapper/dists/gradle-4.6-rc-2-bin/i9k061yvx88h1m14v3gggcj3/gradle-4.6-rc-2/lib/groovy-all-2.4.12.jar) to method java.lang.Object.finalize()
WARNING: Please consider reporting this to the maintainers of org.codehaus.groovy.reflection.CachedClass
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

------------------------------------------------------------
Gradle 4.6-rc-2
------------------------------------------------------------

Build time:   2018-02-21 15:28:42 UTC
Revision:     819e0059da49f469d3e9b2896dc4e72537c4847d

Groovy:       2.4.12
Ant:          Apache Ant(TM) version 1.9.9 compiled on February 2 2017
JVM:          10 ("Oracle Corporation" 10+44)
OS:           Mac OS X 10.13.3 x86_64

[blindpirate]

Closed by #4759