hghave: skip emacs tests on 24.3 and earlier

Turns out with-eval-after-load is new in 24.4.

Differential Revision: https://phab.mercurial-scm.org/D6074

tests/hghave.py

@@ -825,4 +825,7 b' def has_vcr():'
 
 @check('emacs', 'GNU Emacs')
 def has_emacs():
-    return matchoutput('emacs --version', b'GNU Emacs')
+    # Our emacs lisp uses `with-eval-after-load` which is new in emacs
+    # 24.4, so we allow emacs 24.4, 24.5, and 25+ (24.5 was the last
+    # 24 release)
+    return matchoutput('emacs --version', b'GNU Emacs 2(4.4|4.5|5|6|7|8|9)')