add support for reading macros.  This does all the reading (with a bunch of
fixme's, e.g. for tokens with identifiers) but does not actually install
them.  Some details with the predefines buffer needs to be sorted out first.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@68828 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index a31c0c7..09080d6 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -573,6 +573,8 @@
   // macros.
   for (Preprocessor::macro_iterator I = PP.macro_begin(), E = PP.macro_end();
        I != E; ++I) {
+    // FIXME: This emits macros in hash table order, we should do it in a stable
+    // order so that output is reproducible.
     MacroInfo *MI = I->second;
 
     // Don't emit builtin macros like __LINE__ to the PCH file unless they have