run-tests: allow different extra weight for slow tests

The 'test-check-code-hg.t' file is not big enough to be prioritized properly.
As a result my tests run often spend about 15 seconds running only it at the
end of its tests run. We make the "slow" mechanism a bit smarter to adjust the
extra weight of each category independently in a future patch.

tests/run-tests.py

@@ -1662,7 +1662,10 b' class TestRunner(object):'
             random.shuffle(tests)
         else:
             # keywords for slow tests
-            slow = b'svn gendoc check-code-hg'.split()
+            slow = {b'svn': 10,
+                    b'gendoc': 10,
+                    b'check-code-hg': 10,
+                   }
             def sortkey(f):
                 # run largest tests first, as they tend to take the longest
                 try:
@@ -1671,9 +1674,9 b' class TestRunner(object):'
                     if e.errno != errno.ENOENT:
                         raise
                     return -1e9 # file does not exist, tell early
-                for kw in slow:
+                for kw, mul in slow.iteritems():
                     if kw in f:
-                        val *= 10
+                        val *= mul
                 return val
             tests.sort(key=sortkey)