Fix last change in etags.c, which failed the test suite

* lib-src/etags.c (intoken): Add '$' to the set, as it was there
before the last change.

lib-src/etags.c

@@ -194,6 +194,7 @@ static bool
 intoken (unsigned char c)
 {
   static bool const table[UCHAR_MAX + 1] = {
+    ['$']=1,
     ['0']=1, ['1']=1, ['2']=1, ['3']=1, ['4']=1,
     ['5']=1, ['6']=1, ['7']=1, ['8']=1, ['9']=1,
     ['A']=1, ['B']=1, ['C']=1, ['D']=1, ['E']=1, ['F']=1, ['G']=1, ['H']=1,