Use of var in an enhanced for loop causes NullPointerException

[anthonyvdotbe]

To reproduce:

• build ca529a2 with mvn clean verify
• create Foo.java in core\target:

class Foo {

    void run() {
        for (var arg : List.of()) {}
    }

}

• in core\target, run java -jar google-java-format-1.8-SNAPSHOT-all-deps.jar Foo.java
• a NullPointerException occurs at https://github.com/google/google-java-format/blob/master/core/src/main/java/com/google/googlejavaformat/java/DimensionHelpers.java#L109:

Foo.java:4:15: error: java.lang.NullPointerException
        at com.google.googlejavaformat.java.DimensionHelpers.extractDims(DimensionHelpers.java:109)
        at com.google.googlejavaformat.java.DimensionHelpers.extractDims(DimensionHelpers.java:58)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.visitToDeclare(JavaInputAstVisitor.java:2564)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.visitEnhancedForLoop(JavaInputAstVisitor.java:763)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.visitEnhancedForLoop(JavaInputAstVisitor.java:158)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCEnhancedForLoop.accept(JCTree.java:1190)
        at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:82)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.scan(JavaInputAstVisitor.java:330)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.visitStatements(JavaInputAstVisitor.java:2167)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.methodBody(JavaInputAstVisitor.java:1496)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.visitMethod(JavaInputAstVisitor.java:1483)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.visitMethod(JavaInputAstVisitor.java:158)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCMethodDecl.accept(JCTree.java:916)
        at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:82)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.scan(JavaInputAstVisitor.java:330)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.addBodyDeclarations(JavaInputAstVisitor.java:3510)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.visitClassDeclaration(JavaInputAstVisitor.java:1990)
        at com.google.googlejavaformat.java.java14.Java14InputAstVisitor.visitClass(Java14InputAstVisitor.java:81)
        at com.google.googlejavaformat.java.java14.Java14InputAstVisitor.visitClass(Java14InputAstVisitor.java:45)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCClassDecl.accept(JCTree.java:823)
        at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:82)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.scan(JavaInputAstVisitor.java:330)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.visitCompilationUnit(JavaInputAstVisitor.java:375)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.visitCompilationUnit(JavaInputAstVisitor.java:158)
        at jdk.compiler/com.sun.tools.javac.tree.JCTree$JCCompilationUnit.accept(JCTree.java:603)
        at jdk.compiler/com.sun.source.util.TreePathScanner.scan(TreePathScanner.java:82)
        at com.google.googlejavaformat.java.JavaInputAstVisitor.scan(JavaInputAstVisitor.java:330)
        at com.google.googlejavaformat.java.Formatter.format(Formatter.java:170)
        at com.google.googlejavaformat.java.Formatter.getFormatReplacements(Formatter.java:291)
        at com.google.googlejavaformat.java.Formatter.formatSource(Formatter.java:267)
        at com.google.googlejavaformat.java.FormatFileCallable.call(FormatFileCallable.java:45)
        at com.google.googlejavaformat.java.FormatFileCallable.call(FormatFileCallable.java:26)
        at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
        at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1130)
        at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:630)
        at java.base/java.lang.Thread.run(Thread.java:832)