NPE in org.eclipse.jdt.internal.compiler.ast.ReferenceExpression.copy

Found this error in the log, no idea how to reproduce:

```
eclipse.buildId=4.28.0.I20230313-0110
java.version=17.0.4-internal
java.vendor=N/A
BootLoader constants: OS=linux, ARCH=x86_64, WS=gtk, NL=en_US
Command-line arguments: -data /data/4x_platform_workspace -os linux -ws gtk -arch x86_64

org.eclipse.ui.workbench
Error
Mon Mar 13 17:14:27 CET 2023
Problems occurred when invoking code from plug-in: "org.eclipse.ui.workbench".

java.lang.NullPointerException: Cannot assign field "original" because "copy" is null
at org.eclipse.jdt.internal.compiler.ast.ReferenceExpression.copy(ReferenceExpression.java:155)
at org.eclipse.jdt.internal.compiler.ast.ReferenceExpression.cachedResolvedCopy(ReferenceExpression.java:972)
at org.eclipse.jdt.internal.compiler.ast.ReferenceExpression.isCompatibleWith(ReferenceExpression.java:1255)
at org.eclipse.jdt.internal.compiler.lookup.PolyTypeBinding.isCompatibleWith(PolyTypeBinding.java:43)
at org.eclipse.jdt.internal.compiler.lookup.Scope.parameterCompatibilityLevel(Scope.java:5079)
at org.eclipse.jdt.internal.compiler.lookup.Scope.parameterCompatibilityLevel(Scope.java:5043)
at org.eclipse.jdt.internal.compiler.lookup.Scope.computeCompatibleMethod(Scope.java:873)
at org.eclipse.jdt.internal.compiler.lookup.Scope.computeCompatibleMethod(Scope.java:798)
at org.eclipse.jdt.internal.compiler.lookup.Scope.findMethod0(Scope.java:1755)
at org.eclipse.jdt.internal.compiler.lookup.Scope.findMethod(Scope.java:1656)
at org.eclipse.jdt.internal.compiler.lookup.Scope.getMethod(Scope.java:3058)
at org.eclipse.jdt.internal.compiler.ast.MessageSend.findMethodBinding(MessageSend.java:1020)
at org.eclipse.jdt.internal.compiler.ast.MessageSend.resolveType(MessageSend.java:835)
at org.eclipse.jdt.internal.compiler.ast.Expression.resolve(Expression.java:1113)
at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolveStatements(AbstractMethodDeclaration.java:662)
at org.eclipse.jdt.internal.compiler.ast.MethodDeclaration.resolveStatements(MethodDeclaration.java:388)
at org.eclipse.jdt.internal.compiler.ast.AbstractMethodDeclaration.resolve(AbstractMethodDeclaration.java:571)
at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:1506)
at org.eclipse.jdt.internal.compiler.ast.TypeDeclaration.resolve(TypeDeclaration.java:1631)
at org.eclipse.jdt.internal.compiler.ast.CompilationUnitDeclaration.resolve(CompilationUnitDeclaration.java:668)
at org.eclipse.jdt.internal.core.hierarchy.HierarchyResolver.resolve(HierarchyResolver.java:872)
at org.eclipse.jdt.internal.core.hierarchy.HierarchyResolver.resolve(HierarchyResolver.java:669)
at org.eclipse.jdt.internal.core.hierarchy.HierarchyBuilder.buildSupertypes(HierarchyBuilder.java:129)
at org.eclipse.jdt.internal.core.hierarchy.IndexBasedHierarchyBuilder.build(IndexBasedHierarchyBuilder.java:170)
at org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.compute(TypeHierarchy.java:323)
at org.eclipse.jdt.internal.core.hierarchy.TypeHierarchy.refresh(TypeHierarchy.java:1319)
at org.eclipse.jdt.internal.core.CreateTypeHierarchyOperation.executeOperation(CreateTypeHierarchyOperation.java:94)
at org.eclipse.jdt.internal.core.JavaModelOperation.run(JavaModelOperation.java:740)
at org.eclipse.jdt.internal.core.JavaModelOperation.runOperation(JavaModelOperation.java:806)
at org.eclipse.jdt.internal.core.SourceType.newSupertypeHierarchy(SourceType.java:858)
at org.eclipse.jdt.internal.core.SourceType.newSupertypeHierarchy(SourceType.java:809)
at org.eclipse.jdt.internal.corext.util.SuperTypeHierarchyCache.getTypeHierarchy(SuperTypeHierarchyCache.java:144)
at org.eclipse.jdt.internal.corext.util.SuperTypeHierarchyCache.getTypeHierarchy(SuperTypeHierarchyCache.java:96)
at org.eclipse.jdt.internal.corext.util.SuperTypeHierarchyCache.getMethodOverrideTester(SuperTypeHierarchyCache.java:105)
at org.eclipse.jdt.ui.OverrideIndicatorLabelDecorator.getOverrideIndicators(OverrideIndicatorLabelDecorator.java:171)
at org.eclipse.jdt.ui.OverrideIndicatorLabelDecorator.computeAdornmentFlags(OverrideIndicatorLabelDecorator.java:136)
at org.eclipse.jdt.ui.OverrideIndicatorLabelDecorator.decorate(OverrideIndicatorLabelDecorator.java:263)
at org.eclipse.ui.internal.decorators.LightweightDecoratorDefinition.decorate(LightweightDecoratorDefinition.java:257)
at org.eclipse.ui.internal.decorators.LightweightDecoratorManager$LightweightRunnable.run(LightweightDecoratorManager.java:105)
at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:45)
at org.eclipse.ui.internal.decorators.LightweightDecoratorManager.decorate(LightweightDecoratorManager.java:360)
at org.eclipse.ui.internal.decorators.LightweightDecoratorManager.getDecorations(LightweightDecoratorManager.java:346)
at org.eclipse.ui.internal.decorators.DecorationScheduler$1.queue(DecorationScheduler.java:419)
at org.eclipse.ui.internal.decorators.DecorationScheduler$1.run(DecorationScheduler.java:397)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:63)
```