Frontend: Support -iframework.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@142418 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 6a7d2ac..05d2e69 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -1450,6 +1450,10 @@
          OPT_iwithsysroot), ie = Args.filtered_end(); it != ie; ++it)
     Opts.AddPath((*it)->getValue(Args), frontend::System, true, false,
                  !(*it)->getOption().matches(OPT_iwithsysroot));
+  for (arg_iterator it = Args.filtered_begin(OPT_iframework),
+         ie = Args.filtered_end(); it != ie; ++it)
+    Opts.AddPath((*it)->getValue(Args), frontend::System, true, true,
+                 true);
 
   // Add the paths for the various language specific isystem flags.
   for (arg_iterator it = Args.filtered_begin(OPT_c_isystem),