Auto reload throws an error after modifying a method of a service

Modifying controllers seems to work fine. Once a service is modified, I get the following stacktrace:

```
File C:\Users\mangelo\IdeaProjects\sandbox4\grails-app\services\sandbox4\CustomerService.groovy changed, recompiling...
Exception in thread "Thread-26" BUG! exception in phase 'semantic analysis' in source unit 'C:\Users\mangelo\IdeaProjects\sandbox4\grails-app\services\sandbox4\CustomerService.groovy' unexpected NullpointerException
at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1089)
at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:645)
at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:623)
at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:600)
at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:579)
at grails.boot.GrailsApp.compileGroovyFile(GrailsApp.groovy:383)
at grails.boot.GrailsApp.recompile(GrailsApp.groovy:369)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:101)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:323)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:351)
at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:64)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:184)
at grails.boot.GrailsApp$_enableDevelopmentModeWatch_closure1.doCall(GrailsApp.groovy:310)
at grails.boot.GrailsApp$_enableDevelopmentModeWatch_closure1.doCall(GrailsApp.groovy)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:101)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:323)
at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:263)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1041)
at groovy.lang.Closure.call(Closure.java:405)
at groovy.lang.Closure.call(Closure.java:399)
at groovy.lang.Closure.run(Closure.java:486)
at java.base/java.lang.Thread.run(Thread.java:834)
Caused by: java.lang.NullPointerException
at org.grails.datastore.gorm.services.implementers.AbstractDetachedCriteriaServiceImplementor.doImplement(AbstractDetachedCriteriaServiceImplementor.groovy:79)
at org.grails.datastore.gorm.services.implementers.AbstractReadOperationImplementer.implement(AbstractReadOperationImplementer.groovy:62)
at org.grails.datastore.gorm.services.transform.ServiceTransformation.visitAfterTraitApplied(ServiceTransformation.groovy:278)
at org.grails.datastore.gorm.transform.AbstractTraitApplyingGormASTTransformation.visit(AbstractTraitApplyingGormASTTransformation.groovy:52)
at org.grails.datastore.gorm.transform.AbstractTraitApplyingGormASTTransformation.visit(AbstractTraitApplyingGormASTTransformation.groovy:42)
at org.grails.datastore.gorm.transform.AbstractGormASTTransformation.visit(AbstractGormASTTransformation.groovy:59)
at org.codehaus.groovy.transform.ASTTransformationVisitor.visitClass(ASTTransformationVisitor.java:145)
at org.codehaus.groovy.transform.ASTTransformationVisitor$2.call(ASTTransformationVisitor.java:189)
at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1084)
... 29 more
```

1. Startup app
2. Go to localhost:8080/customer/1 - should work
3. Modify controller method 'show':
respond customerService.getOne()
4. Again go to localhost:8080/customer/1 - should work
5. Modify CustomerService.getOne() to get a different id (1-3) - this will cause the exception

This project can be found at: https://github.com/mangelo123/sandbox4.git

Reproduce the issue with the sandbox4 project using the listed controller and CustomerService.getOne() steps. Start with the recompile path in GrailsApp.groovy and the reported AbstractDetachedCriteriaServiceImplementor.groovy failure. Done means modifying the service during auto reload no longer throws the semantic-analysis NullPointerException.

Written by the indexing model from the issue text.