Enable Runtime Method Parameter Reflection

Several method security tests rely on method parameters
being preserved, in order to demonstrate the difference
between relying on runtime reflection and using the @P
annotation.

Closes gh-15680

buildSrc/src/main/groovy/io/spring/gradle/convention/EclipsePlugin.groovy

@@ -63,6 +63,7 @@ class EclipsePlugin implements Plugin<Project> {
 						// test sources. Relax those from error to warning
 						properties['org.eclipse.jdt.core.circularClasspath'] = 'warning'
 						properties['org.eclipse.jdt.core.incompleteClasspath'] = 'warning'
+						properties['org.eclipse.jdt.core.compiler.codegen.methodParameters'] = 'generate'
 					}
 				}
 			}