Keep a tabular array initializer with mixed signs in rows

An array initializer written in rows, such as a table of coordinates,
keeps its rows when every column holds expressions of the same kind.
A column that mixed 95.0 with -95.0 or +95.0 did not count as one kind,
because a signed number is a unary expression in javac's tree, so the
whole table collapsed into one line, or into a filled block.

This ports google/google-java-format#406 by Andrew Reid, which fixes
google/google-java-format#400: a unary expression counts as the kind
of its operand for that comparison. The golden
TabularMixedSignInitializer comes from upstream, with the expected
output in this project's style.

The 15,747 files of the JDK 21 sources format exactly as before.

Author: andrewkreid

open-java-format/src/main/java/com/palantir/javaformat/java/JavaInputAstVisitor.java

@@ -3468,7 +3468,13 @@ private static boolean expressionsAreParallel(List<List<ExpressionTree>> rows, i
             if (column >= row.size()) {
                 continue;
             }
-            nodeTypes.add(row.get(column).getKind());
+            // Treat UnaryTree expressions as their underlying type for the comparison (so, for example
+            // -ve and +ve numeric literals are considered the same).
+            if (row.get(column) instanceof UnaryTree) {
+                nodeTypes.add(((UnaryTree) row.get(column)).getExpression().getKind());
+            } else {
+                nodeTypes.add(row.get(column).getKind());
+            }
         }
         for (Multiset.Entry<Tree.Kind> nodeType : nodeTypes.entrySet()) {
             if (nodeType.getCount() >= atLeastM) {

open-java-format/src/test/resources/com/palantir/javaformat/java/testdata/TabularMixedSignInitializer.input

@@ -0,0 +1,17 @@
+public class T {
+  private static final double[] f = {
+    95.0, 75.0, -95.0, 75.0,
+    -95.0, 75.0, +95.0, 75.0
+  };
+
+  private static final int[] g = {
+    x++, y, ++z,
+    x, y, ~z,
+    --x, ++y, z--
+  };
+
+  private static final bool[] h = {
+    a, b, c, d,
+    !e, a, b, c
+  };
+}

open-java-format/src/test/resources/com/palantir/javaformat/java/testdata/TabularMixedSignInitializer.output

@@ -0,0 +1,17 @@
+public class T {
+    private static final double[] f = {
+        95.0, 75.0, -95.0, 75.0,
+        -95.0, 75.0, +95.0, 75.0
+    };
+
+    private static final int[] g = {
+        x++, y, ++z,
+        x, y, ~z,
+        --x, ++y, z--
+    };
+
+    private static final bool[] h = {
+        a, b, c, d,
+        !e, a, b, c
+    };
+}