fileset: perform membership test against set for status queries

Previously, fileset functions operating on status items performed
membership tests against a list of items. When there are thousands
of items having a specific status, that test can be extremely
slow. Changing the membership test to a set makes this operation
substantially faster.

On the mozilla-central repo:

$ hg files -r d14cac631ecc 'set:added()'
before: 28.120s
after:   0.860s

$ hg status --change d14cac631ecc --added
0.690s

mercurial/fileset.py

@@ -154,7 +154,7 b' def modified(mctx, x):'
     """
     # i18n: "modified" is a keyword
     getargs(x, 0, 0, _("modified takes no arguments"))
-    s = mctx.status().modified
+    s = set(mctx.status().modified)
     return [f for f in mctx.subset if f in s]
 
 @predicate('added()', callstatus=True)
@@ -163,7 +163,7 b' def added(mctx, x):'
     """
     # i18n: "added" is a keyword
     getargs(x, 0, 0, _("added takes no arguments"))
-    s = mctx.status().added
+    s = set(mctx.status().added)
     return [f for f in mctx.subset if f in s]
 
 @predicate('removed()', callstatus=True)
@@ -172,7 +172,7 b' def removed(mctx, x):'
     """
     # i18n: "removed" is a keyword
     getargs(x, 0, 0, _("removed takes no arguments"))
-    s = mctx.status().removed
+    s = set(mctx.status().removed)
     return [f for f in mctx.subset if f in s]
 
 @predicate('deleted()', callstatus=True)
@@ -181,7 +181,7 b' def deleted(mctx, x):'
     """
     # i18n: "deleted" is a keyword
     getargs(x, 0, 0, _("deleted takes no arguments"))
-    s = mctx.status().deleted
+    s = set(mctx.status().deleted)
     return [f for f in mctx.subset if f in s]
 
 @predicate('missing()', callstatus=True)
@@ -190,7 +190,7 b' def missing(mctx, x):'
     """
     # i18n: "missing" is a keyword
     getargs(x, 0, 0, _("missing takes no arguments"))
-    s = mctx.status().deleted
+    s = set(mctx.status().deleted)
     return [f for f in mctx.subset if f in s]
 
 @predicate('unknown()', callstatus=True)
@@ -200,7 +200,7 b' def unknown(mctx, x):'
     """
     # i18n: "unknown" is a keyword
     getargs(x, 0, 0, _("unknown takes no arguments"))
-    s = mctx.status().unknown
+    s = set(mctx.status().unknown)
     return [f for f in mctx.subset if f in s]
 
 @predicate('ignored()', callstatus=True)
@@ -210,7 +210,7 b' def ignored(mctx, x):'
     """
     # i18n: "ignored" is a keyword
     getargs(x, 0, 0, _("ignored takes no arguments"))
-    s = mctx.status().ignored
+    s = set(mctx.status().ignored)
     return [f for f in mctx.subset if f in s]
 
 @predicate('clean()', callstatus=True)
@@ -219,7 +219,7 b' def clean(mctx, x):'
     """
     # i18n: "clean" is a keyword
     getargs(x, 0, 0, _("clean takes no arguments"))
-    s = mctx.status().clean
+    s = set(mctx.status().clean)
     return [f for f in mctx.subset if f in s]
 
 def func(mctx, a, b):