[PATCH 4 of 8] py3: fix mixed bytes/unicode in revsetlang._aliassyminitletters

[Yuya Nishihara]

# HG changeset patch
# User Yuya Nishihara <yuya at tcha.org>
# Date 1504425803 -32400
#      Sun Sep 03 17:03:23 2017 +0900
# Node ID 4a0d22cd832998cc6211e4becf23d5e08a84058d
# Parent  004d163d1bbc31825c134eb4d43e60b11ced61ca
py3: fix mixed bytes/unicode in revsetlang._aliassyminitletters

diff --git a/mercurial/revsetlang.py b/mercurial/revsetlang.py
--- a/mercurial/revsetlang.py
+++ b/mercurial/revsetlang.py
@@ -473,7 +473,7 @@ def optimize(tree):
 
 # the set of valid characters for the initial letter of symbols in
 # alias declarations and definitions
-_aliassyminitletters = _syminitletters | set(pycompat.sysstr('$'))
+_aliassyminitletters = _syminitletters | {'$'}
 
 def _parsewith(spec, lookup=None, syminitletters=None):
     """Generate a parse tree of given spec with given tokenizing options