Completion for import module |;

This is new Java 23 syntax.
This PR should make 6 new tests pass
(mostly from the java 23 completion suite)
This PR also incorporates
eclipse-jdt#3479,
I forget specifically why, but it's needed.

- Fixes to the javac AST converter
  - I did a hack in the converter to recover the following case,
    since javac doesn't handle it currently:

```java
import module

public class HelloWorld {
}
```

- Adjust module completion relevance based on if it's required by the current
  module

Signed-off-by: David Thompson <davthomp@redhat.com>

org.eclipse.jdt.core.javac/src/org/eclipse/jdt/core/dom/JavacConverter.java

@@ -93,6 +93,7 @@
 import com.sun.tools.javac.tree.JCTree.JCMethodInvocation;
 import com.sun.tools.javac.tree.JCTree.JCModifiers;
 import com.sun.tools.javac.tree.JCTree.JCModuleDecl;
+import com.sun.tools.javac.tree.JCTree.JCModuleImport;
 import com.sun.tools.javac.tree.JCTree.JCNewArray;
 import com.sun.tools.javac.tree.JCTree.JCNewClass;
 import com.sun.tools.javac.tree.JCTree.JCOpens;
@@ -192,6 +193,9 @@ void populateCompilationUnit(CompilationUnit res, JCCompilationUnit javacCompila
 			res.setModule(convert(javacCompilationUnit.getModuleDecl()));
 		}
 		javacCompilationUnit.getImports().stream().filter(imp -> imp instanceof JCImport).map(jc -> convert((JCImport)jc)).forEach(res.imports()::add);
+		if (this.ast.apiLevel >= AST.JLS23_INTERNAL) {
+			javacCompilationUnit.getImports().stream().filter(imp -> imp instanceof JCModuleImport).map(jc -> convert((JCModuleImport)jc)).forEach(res.imports()::add);
+		}
 		javacCompilationUnit.getTypeDecls().stream()
 			.map(n -> convertBodyDeclaration(n, res))
 			.filter(Objects::nonNull)
@@ -394,6 +398,14 @@ private ImportDeclaration convert(JCImport javac) {
 		if (select.getIdentifier().contentEquals("*")) {
 			res.setOnDemand(true);
 			res.setName(toName(select.getExpression()));
+		} else if (this.ast.apiLevel >= AST.JLS23_INTERNAL && select.selected.toString().equals("module") && select.name.toString().equals("<error>")) {
+			// it's a broken module import
+			var moduleModifier = this.ast.newModifier(ModifierKeyword.MODULE_KEYWORD);
+			res.modifiers().add(moduleModifier);
+			Name name = new SimpleName(this.ast);
+			name.setSourceRange(res.getStartPosition() + res.getLength() + 1, 0);
+			res.setName(name);
+			res.setSourceRange(res.getStartPosition(), res.getLength() + 1);
 		} else {
 			res.setName(toName(select));
 		}
@@ -423,6 +435,21 @@ private ImportDeclaration convert(JCImport javac) {
 		}
 		return res;
 	}
+
+	private ImportDeclaration convert(JCModuleImport javac) {
+		ImportDeclaration res = this.ast.newImportDeclaration();
+		commonSettings(res, javac);
+		var moduleModifier = this.ast.newModifier(ModifierKeyword.MODULE_KEYWORD);
+		res.modifiers().add(moduleModifier);
+		if (javac.isStatic()) {
+			if( this.ast.apiLevel != AST.JLS2_INTERNAL) {
+				res.setStatic(true);
+			}
+		}
+		var select = javac.getQualifiedIdentifier();
+		res.setName(toName(select));
+		return res;
+	}
 
 	void commonSettings(ASTNode res, JCTree javac) {
 		if( javac != null ) {

org.eclipse.jdt.core.javac/src/org/eclipse/jdt/internal/javac/JavacProblemConverter.java

@@ -1080,6 +1080,7 @@ yield switch (rootCauseCode) {
 			case "compiler.err.void.not.allowed.here" -> IProblem.ParameterMismatch;
 			case "compiler.err.abstract.cant.be.accessed.directly" -> IProblem.DirectInvocationOfAbstractMethod;
 			case "compiler.warn.annotation.method.not.found" -> IProblem.UndefinedAnnotationMember;
+			case "compiler.err.import.module.not.found" -> IProblem.UndefinedModule;
 			default -> {
 				ILog.get().error("Could not accurately convert diagnostic (" + diagnostic.getCode() + ")\n" + diagnostic);
 				if (diagnostic.getKind() == javax.tools.Diagnostic.Kind.ERROR && diagnostic.getCode().startsWith("compiler.err")) {