tools: allow test.py to use full paths of tests

Allow test.py to run tests with a 'tests/' prefix or a '.js' postfix

PR-URL: https://github.com/nodejs/node/pull/9694
Fixes: https://github.com/nodejs/node/issues/9684
Reviewed-By: Prince John Wesley <princejohnwesley@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>

tools/test.py

@@ -1476,6 +1476,13 @@ def SplitPath(s):
   stripped = [ c.strip() for c in s.split('/') ]
   return [ Pattern(s) for s in stripped if len(s) > 0 ]
 
+def NormalizePath(path):
+  # strip the extra path information of the specified test
+  if path.startswith('test/'):
+    path = path[5:]
+  if path.endswith('.js'):
+    path = path[:-3]
+  return path
 
 def GetSpecialCommandProcessor(value):
   if (not value) or (value.find('@') == -1):
@@ -1548,7 +1555,7 @@ def Main():
   else:
     paths = [ ]
     for arg in args:
-      path = SplitPath(arg)
+      path = SplitPath(NormalizePath(arg))
       paths.append(path)
 
   # Check for --valgrind option. If enabled, we overwrite the special