support emcc -v with no further arguments

emcc

@@ -297,6 +297,9 @@ the source of emcc (search for 'os.environ').
 
 ''' % (this, this, this)
   exit(0)
+elif len(sys.argv) == 2 and sys.argv[1] == '-v': # -v with no inputs
+  print 'emcc (Emscripten GCC-like replacement) 2.0'
+  exit(subprocess.call([shared.CLANG, '-v']))
 
 # If this is a configure-type thing, do not compile to JavaScript, instead use clang
 # to compile to a native binary (using our headers, so things make sense later)

tests/runner.py

@@ -6305,6 +6305,10 @@ This is free and open source software under the MIT license.
 There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 ''', output[0].replace('\r', ''), output[1].replace('\r', ''))
 
+        # -v, without input files
+        output = Popen(['python', compiler, '-v'], stdout=PIPE, stderr=PIPE).communicate()
+        self.assertContained('''clang version''', output[1].replace('\r', ''), output[1].replace('\r', ''))
+
         # --help
         output = Popen(['python', compiler, '--help'], stdout=PIPE, stderr=PIPE).communicate()
         self.assertContained('''%s [options] file...