[Releng] Use new Temurin JDKs for Java 18.
diff --git a/releng/org.eclipse.justj.releng/Jenkinsfile b/releng/org.eclipse.justj.releng/Jenkinsfile
index cd8bfc1..f411b69 100644
--- a/releng/org.eclipse.justj.releng/Jenkinsfile
+++ b/releng/org.eclipse.justj.releng/Jenkinsfile
@@ -57,7 +57,7 @@
   PROMOTE: 'true'
 ]
 
-// Tags jdk-17.0.2+8, jdk-17.0.1+12
+// Tags jdk-17.0.2+8, jdk-17.0.1+12, jdk-17+35
 def java17Adoptium = [
   label: 'Java 17 (Adoptium)',
   BUILD_DESCRIPTION: 'Build Adoptium Java 17',
@@ -82,6 +82,31 @@
   PROMOTE: 'true'
 ]
 
+// Tags jdk-18+36
+def java18Adoptium = [
+  label: 'Java 18 (Adoptium)',
+  BUILD_DESCRIPTION: 'Build Adoptium Java 18',
+  PUBLISH_LOCATION_PREFIX: "${defaultPrefix}",
+  JUSTJ_MANIFEST_URL: "${justjURL}/${defaultPrefix}/18/downloads/latest/justj.manifest",
+  JDK_URLS_WINDOWS: '''
+    https://github.com/adoptium/temurin18-binaries/releases/download/jdk-18+36/OpenJDK18U-jdk_x64_windows_hotspot_18_36.zip
+    ''',
+  JDK_URLS_MACOS: '''
+    https://github.com/adoptium/temurin18-binaries/releases/download/jdk-18+36/OpenJDK18U-jdk_x64_mac_hotspot_18_36.tar.gz
+    ''',
+  JDK_URLS_MACOS_AARCH64: '''
+    https://github.com/adoptium/temurin18-binaries/releases/download/jdk-18+36/OpenJDK18U-jdk_aarch64_mac_hotspot_18_36.tar.gz
+    ''',
+  JDK_URLS_LINUX: '''
+    https://github.com/adoptium/temurin18-binaries/releases/download/jdk-18+36/OpenJDK18U-jdk_x64_linux_hotspot_18_36.tar.gz
+    ''',
+  JDK_URLS_LINUX_AARCH64: '''
+    https://github.com/adoptium/temurin18-binaries/releases/download/jdk-18+36/OpenJDK18U-jdk_aarch64_linux_hotspot_18_36.tar.gz
+    ''',
+  BUILD_TYPE: 'nightly',
+  PROMOTE: 'true'
+]
+
 def java14 = [
   label: 'Java 14 (test)',
   BUILD_DESCRIPTION: 'Build jdk.java.net Java 14 (-test)',