Only zap the igen directory once.

sim/.Sanitize

@@ -15,16 +15,20 @@
 
 Do-first:
 
-d30v_files="d30v igen testsuite"
+igen_files="igen"
+
+d30v_files="d30v testsuite"
 if ( echo $* | grep keep\-d30v > /dev/null ) ; then
-        keep_these_too="${d30v_files} ${keep_these_too}"
+        keep_these_too="${d30v_files} ${igen_files} ${keep_these_too}"
+	igen_files=
 else
         lose_these_too="${d30v_files} ${lose_these_too}"
 fi
 
-tic80_files="tic80 igen"
+tic80_files="tic80"
 if ( echo $* | grep keep\-tic80 > /dev/null ) ; then
-        keep_these_too="${tic80_files} ${keep_these_too}"
+        keep_these_too="${tic80_files} ${igen_files} ${keep_these_too}"
+	igen_files=
 else
         lose_these_too="${tic80_files} ${lose_these_too}"
 fi
@@ -36,6 +40,8 @@ else
         lose_these_too="${v850_files} ${lose_these_too}"
 fi
 
+lose_these_too="${igen_files} ${lose_these_too}"
+
 # All files listed between the "Things-to-keep:" line and the
 # "Files-to-sed:" line will be kept.  All other files will be removed.
 # Directories listed in this section will have their own Sanitize