8335880: More troubleshooting tips around windows space in path

doc/building.html

@@ -2019,14 +2019,18 @@ <h4 id="spaces-in-path">Spaces in Path</h4>
 have <a
 href="https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/fsutil-8dot3name">short
 paths</a>. You can run <code>fsutil file setshortname</code> in
-<code>cmd</code> on directories to assign short paths so
+<code>cmd</code> on directories to assign arbitrary short paths so
 <code>configure</code> can access them. If the result says "Access
 denied", it may be that there are processes running in that directory;
-you can reboot Windows in safe mode and run the command on those
-directories again.</p>
+in this case, you can reboot Windows in safe mode and run the command on
+those directories again.</p>
 <p>The only directories required to have short paths are
 <code>Microsoft Visual Studio</code> and <code>Windows Kits</code>; the
-rest of the "contains space" warnings from configure can be ignored.</p>
+rest of the "contains space" warnings from <code>configure</code> can be
+ignored. You can choose any short name; once it is set,
+<code>configure</code>'s tools like <code>cygpath</code> can convert the
+directory with spaces to your chosen short name and pass it to the build
+system.</p>
 <h3 id="getting-help">Getting Help</h3>
 <p>If none of the suggestions in this document helps you, or if you find
 what you believe is a bug in the build system, please contact the Build