[frontend] Don't put a PCH/PTH filename into the set of includes in the preprocessor options;
since only one of them is allowed in command-line, process them separately.

Otherwise, if more than one is specified in the command-line, one is processed normally
and the others are going to be treated and included as header files.

Related to radar://13140508

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174385 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index a2b28bc..a4597fd 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -1345,8 +1345,7 @@
   Opts.MacroIncludes = Args.getAllArgValues(OPT_imacros);
 
   // Add the ordered list of -includes.
-  for (arg_iterator it = Args.filtered_begin(OPT_include, OPT_include_pch,
-                                             OPT_include_pth),
+  for (arg_iterator it = Args.filtered_begin(OPT_include),
          ie = Args.filtered_end(); it != ie; ++it) {
     const Arg *A = *it;
     Opts.Includes.push_back(A->getValue());