Add support for Java 20 (#224)

Author: uschindler

build.xml

@@ -67,6 +67,7 @@
       <equals arg1="${-cleaned.specification.version}" arg2="17"/>
       <equals arg1="${-cleaned.specification.version}" arg2="18"/>
       <equals arg1="${-cleaned.specification.version}" arg2="19"/>
+      <equals arg1="${-cleaned.specification.version}" arg2="20"/>
     </or>
   </condition>
 
@@ -165,6 +166,7 @@
       <equals arg1="${build.java.runtime}" arg2="17"/>
       <equals arg1="${build.java.runtime}" arg2="18"/>
       <equals arg1="${build.java.runtime}" arg2="19"/>
+      <!-- Java 20 for testing is no longer supported as Java 7 support was removed as compile target -->
     </or>
   </condition>
 

ivy.xml

@@ -17,7 +17,7 @@
 <!DOCTYPE ivy-module [
   <!ENTITY maven.version "2.0">
   <!ENTITY gradle.version "3.4">
-  <!ENTITY asm.version "9.4">
+  <!ENTITY asm.version "9.5">
   <!ENTITY jarjar.asm.version "5.2">
 ]>
 <ivy-module version="2.0">

src/main/docs/bundled-signatures.html

@@ -29,14 +29,14 @@ <h1>Bundled Signatures Documentation</h1>
 <li><strong><tt>jdk-unsafe-*</tt>:</strong> Signatures
 of &quot;unsafe&quot; methods that use default charset, default locale, or default timezone. For server applications it is very
 stupid to call those methods, as the results will definitely not what the user wants
-(for Java <tt>*</tt> = 1.7, 1.8, 9,..., 19; Ant / Maven / Gradle automatically add the compile Java version).</li>
+(for Java <tt>*</tt> = 1.7, 1.8, 9,..., 20; Ant / Maven / Gradle automatically add the compile Java version).</li>
 
 <li><strong><tt>jdk-deprecated-*</tt>:</strong> This disallows all deprecated
-methods from the JDK (for Java <tt>*</tt> = 1.7, 1.8, 9,..., 19; Ant / Maven / Gradle automatically add the compile Java version).</li>
+methods from the JDK (for Java <tt>*</tt> = 1.7, 1.8, 9,..., 20; Ant / Maven / Gradle automatically add the compile Java version).</li>
 
 <li><strong><tt>jdk-internal-*</tt>:</strong> Lists all internal packages of the JDK as of <code>Security.getProperty(&quot;package.access&quot;)</code>.
 Calling those methods will always trigger security manager and is completely forbidden from Java 9 on
-(for Java <tt>*</tt> = 1.7, 1.8, 9,..., 19; Ant / Maven / Gradle automatically add the compile Java version, <em>since forbiddenapis v2.1</em>).</li>
+(for Java <tt>*</tt> = 1.7, 1.8, 9,..., 20; Ant / Maven / Gradle automatically add the compile Java version, <em>since forbiddenapis v2.1</em>).</li>
 
 <li><strong><tt>jdk-non-portable</tt>:</strong> Signatures of all non-portable (like <code>com.sun.management.HotSpotDiagnosticMXBean</code>)
 or internal runtime APIs (like <code>sun.misc.Unsafe</code>). This is a superset of <tt>jdk-internal</tt>.<br>

src/main/java/de/thetaphi/forbiddenapis/AsmUtils.java

@@ -180,7 +180,7 @@ private static byte[] readStream(final InputStream in) throws IOException {
   @SuppressWarnings("unused")
   public static ClassReader readAndPatchClass(InputStream in) throws IOException {
     final byte[] bytecode = readStream(in);
-    if (false) patchClassMajorVersion(bytecode, Opcodes.V19 + 1, Opcodes.V19);
+    if (false) patchClassMajorVersion(bytecode, Opcodes.V21 + 1, Opcodes.V21);
     return new ClassReader(bytecode);
   }