depgen: Combine preproc:symtable sym-ref generation cases

This does not impact performance, but it makes it less confusing.  What a
mess this whole thing is.  I'll have to incrementally refactor it until it
makes sense enough to optimize.

For this who don't know, from XSLT 1.0 days: "rtf" means "result tree
fragment", before sequences were a thing, and you had to treat generated
trees specially.  Yeah, old code.

DEV-15114

src/current/include/depgen.xsl

@@ -142,7 +142,7 @@
 
       <!-- grab the original source symbol for these references and augment them
            with any additional dependency metadata -->
-      <variable name="syms-rtf">
+      <variable name="syms" as="element( preproc:sym )*">
         <for-each select="$uniq">
           <variable name="name" select="@name" />
           <variable name="sym" as="element( preproc:sym )?"
@@ -178,8 +178,6 @@
         </for-each>
       </variable>
 
-      <variable name="syms" select="$syms-rtf/preproc:sym" />
-
       <!-- only applicable if the symbol is @lax and the symbol was not
            found in the local symbol table -->
       <variable name="lax" select="
@@ -202,24 +200,17 @@
         </for-each>
 
         <!-- @tex provided an non-empty, or function -->
-        <for-each select="
-          $syms[
-            ( @tex and not( @tex='' ) )
-            or @type='func'
-          ]">
-
+        <for-each select="$syms">
+          <preproc:sym-ref>
             <choose>
               <!-- even if function, @tex overrides symbol -->
               <when test="@tex and not( @tex='' )">
-              <preproc:sym-ref tex="{@tex}">
+                <attribute name="tex" select="@tex" />
                 <sequence select="@*" />
                 <sequence select="preproc:meta/@*" />
-              </preproc:sym-ref>
               </when>
 
-            <!-- must be a function; use its name -->
-            <otherwise>
-              <preproc:sym-ref>
+              <when test="@type = 'func'">
                 <sequence select="@*" />
                 <sequence select="preproc:meta/@*" />
 
@@ -228,22 +219,12 @@
                     <value-of select="@name" />
                   <text>}</text>
                 </attribute>
-              </preproc:sym-ref>
-            </otherwise>
-          </choose>
-        </for-each>
-
-        <!-- no @tex, @tex empty, no function -->
-        <for-each select="
-          $syms[
-            ( not( @tex ) or @tex='' )
-            and not( @type='func' )
-          ]">
+              </when>
 
+              <otherwise>
                 <variable name="name" select="@name" />
                 <variable name="sym" select="." />
 
-          <preproc:sym-ref>
                 <!-- minimal attribute copy (avoid data duplication as much as
                      possible to reduce modification headaches later on) -->
                 <sequence select="@name, @parent" />
@@ -253,9 +234,7 @@
                 <variable name="pos" select="position()" />
                 <attribute name="tex">
                   <variable name="texsym" select="
-                  $tex-defaults/preproc:syms/preproc:sym[
-                    position() = $pos
-                  ]
+                      $tex-defaults/preproc:syms/preproc:sym[ $pos ]
                     " />
 
                   <choose>
@@ -285,6 +264,8 @@
                     </otherwise>
                   </choose>
                 </attribute>
+              </otherwise>
+            </choose>
           </preproc:sym-ref>
         </for-each>
       </preproc:sym-dep>