Add regression test for path w/ trailing wildcard

This patch demonstrates a corner case in the path glob matcher.
Specifically, it documents how a single trailing asterisk is supposed
to be treated as opposed to a double asterisk.
With [[1]], a trailing `/*` is interpreted as an equivalent of `/**`.
The commit add a case that shows that `/*` shouldn't be greedy as
described in the docs [[2]][[3]].

See also the observations in the bug report ticket [[4]].

[1]: nedbat@ec6205a
[2]: https://coverage.rtfd.io/en/stable/source.html#file-patterns
[3]: https://coverage.rtfd.io/en/7.2.7/migrating.html#migrating-to-coverage-py-7-x
[4]: nedbat#1407 (comment)

tests/test_files.py

@@ -348,11 +348,14 @@ def test_glob_matcher(self) -> None:
             (self.make_file("sub/file1.py"), True),
             (self.make_file("sub/file2.c"), False),
             (self.make_file("sub2/file3.h"), True),
+            (self.make_file("sub2/sub/file3.h"), False),
             (self.make_file("sub3/file4.py"), True),
             (self.make_file("sub3/file5.c"), False),
+            (self.make_file("sub4/file3.h"), True),
+            (self.make_file("sub4/sub/file3.h"), True),
         ]
-        fnm = GlobMatcher(["*.py", "*/sub2/*"])
-        assert fnm.info() == ["*.py", "*/sub2/*"]
+        fnm = GlobMatcher(["*.py", "*/sub2/*", "*/sub4/**"])
+        assert fnm.info() == ["*.py", "*/sub2/*", "*/sub4/**"]
         for filepath, matches in matches_to_try:
             self.assertMatches(fnm, filepath, matches)