add missing Reflection support from 2020 tag

src/main/java/org/teavm/classlib/support/ReflectionSupplierImpl.java

+package org.teavm.classlib.support;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.teavm.classlib.ReflectionContext;
+import org.teavm.classlib.ReflectionSupplier;
+import org.teavm.model.ClassReader;
+import org.teavm.model.MethodDescriptor;
+import org.teavm.model.MethodReader;
+
+public class ReflectionSupplierImpl implements ReflectionSupplier {
+	@Override
+	public Collection<String> getAccessibleFields(ReflectionContext context, String className) {
+		return Collections.emptyList();
+	}
+
+	private static Set<String> REFLECTABLE = new TreeSet() {{
+		add("Temperature3::setTemperature");
+		add("EauChaude6::getEtatφ");
+		add("generique.AimeLesChats::getAnimalDeCompagnie");
+	}};
+	@Override
+	public Collection<MethodDescriptor> getAccessibleMethods(ReflectionContext context, String className) {
+		if (className.contains(".")
+			&& !className.startsWith("generique."))
+			return Collections.emptyList();
+		ClassReader cls = context.getClassSource().get(className);
+		if (cls == null)
+			return Collections.emptyList();
+		Set<MethodDescriptor> methods = new HashSet<>();
+		for (MethodReader method : cls.getMethods())
+			if (REFLECTABLE.contains(className+"::"+method.getName()))
+				methods.add(method.getDescriptor());
+		return methods;
+	}
+}
\ No newline at end of file

src/main/resources/META-INF/services/org.teavm.classlib.ReflectionSupplier

+org.teavm.classlib.support.ReflectionSupplierImpl