Add future to lock in the bug I found with chpldoc linking behavior (c…

…hapel-lang#24641)

[new test, not reviewed]

The documentation for a nested record can't link to symbols defined at
the same level as it. This should be something it can do (and is
something it can do for functions defined at the same level)

Verified a fresh checkout of the test behaved as expected

test/chpldoc/links/linkToPrev.doc.bad

@@ -0,0 +1 @@
+Could not find link for reference '#linkToPrev.func1'

test/chpldoc/links/linkToPrev.doc.chpl

@@ -0,0 +1,10 @@
+module linkToPrev {
+  record foo {
+    proc func1() { }
+
+    // Seems to only be a problem for record's referring to functions at the
+    // same level and when they are both in another type
+    /* Returned by :proc:`func1` */
+    record innerFoo { }
+  }
+}

test/chpldoc/links/linkToPrev.doc.chpldocopts

@@ -0,0 +1 @@
+-o docs

test/chpldoc/links/linkToPrev.doc.cleanfiles

@@ -0,0 +1 @@
+docs

test/chpldoc/links/linkToPrev.doc.future

@@ -0,0 +1,2 @@
+bug: can't link from nested type to sibling symbols
+#24625

test/chpldoc/links/linkToPrev.doc.good

@@ -0,0 +1 @@
+Found link for reference '#linkToPrev.func1'

test/chpldoc/links/linkToPrev.doc.prediff

@@ -0,0 +1,28 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+import re
+
+testname = sys.argv[1]
+testout = sys.argv[2]
+
+html_file = f"docs/modules/linkToPrev.html"
+if not os.path.exists(html_file):
+    with open(testout, "w") as f:
+        print(f"Could not find '{html_file}'", file=f)
+    exit()
+
+html_output = ""
+with open(html_file, "r") as f:
+    html_output = f.read()
+
+output = []
+
+if not re.search(f'<a class="reference internal" href="#linkToPrev.func1" title="linkToPrev2.func1">', html_output):
+    output.append(f"Could not find link for reference '#linkToPrev.func1'")
+else:
+    output.append(f"Found link for reference '#linkToPrev.func1'")
+
+with open(testout, "w") as f:
+    print("\n".join(output), file=f)