match: compose 'set:' pattern as matcher
Baby step towards porting fileset to matcher composition.
We can't use the exactmatcher since it would provide a computed set as exact
paths. That's why we use the predicatematcher with fset.__contains__. This
will be cleaned up later.
The test change in test-glog.t means that the "set:copied()" pattern is no
longer be processed as a slow path. That's because the fset is empty. This
will also change in future patches.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..