Don't try to compile .a files.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@46626 91177308-0d34-0410-b5e6-96231b3b80d8

utils/ccc

@@ -84,7 +84,7 @@ def main(args):
             link_opts.append(arg)
         
         # Options with one argument that should be ignored
-        if arg in ['--param', '-arch']:
+        if arg in ['--param', '-arch', '-u']:
             i += 1
 
         # Prefix matches for the compile mode
@@ -183,7 +183,8 @@ def main(args):
 
     if action == 'link':
         for i, file in enumerate(files):
-            if extension(file) != "o":
+            ext = extension(file)
+            if ext != "o" and ext != "a":
                 out = changeextension(file, "o")
                 args = ['-o', out, file] + compile_opts
                 compile(args)