Bug 553037 - Fails to compile with Java 11

Use maven.compiler.release option that's added in Tycho 1.6.0-SNAPSHOT
to say which version to compile against.
This will make maven compile fail when run on Java 8 but it's a fine
workaround now that we expect to be building with Java 11.

Change-Id: I9fc18d1b123a32b86639301c8c77184ed7ad4cde
Signed-off-by: Alexander Kurtakov <akurtako@redhat.com>
diff --git a/org.eclipse.jdt.debug/pom.xml b/org.eclipse.jdt.debug/pom.xml
index c301bb6..cc291ad 100644
--- a/org.eclipse.jdt.debug/pom.xml
+++ b/org.eclipse.jdt.debug/pom.xml
@@ -20,4 +20,7 @@
   <artifactId>org.eclipse.jdt.debug</artifactId>
   <version>3.14.100-SNAPSHOT</version>
   <packaging>eclipse-plugin</packaging>
+  <properties>
+    <maven.compiler.release>8</maven.compiler.release>
+  </properties>
 </project>
diff --git a/org.eclipse.jdt.launching/pom.xml b/org.eclipse.jdt.launching/pom.xml
index 5376a65..d8504a3 100644
--- a/org.eclipse.jdt.launching/pom.xml
+++ b/org.eclipse.jdt.launching/pom.xml
@@ -20,6 +20,9 @@
   <artifactId>org.eclipse.jdt.launching</artifactId>
   <version>3.17.0-SNAPSHOT</version>
   <packaging>eclipse-plugin</packaging>
+  <properties>
+    <maven.compiler.release>8</maven.compiler.release>
+  </properties>
   
   <build>
         <plugins>