[Frontend] Add an ExternCSystem include entry group.

 - The only group where it makes sense for the "ExternC" bit is System, so this
   simplifies having to have the extra isCXXAware (or ImplicitExternC, depending
   on what code you talk to) bit caried around.

llvm-svn: 173859

2 files changed, 1 insertions, 3 deletions

diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 8a8f6a2cfe9..c07e1e9982f 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3692,10 +3692,9 @@ bool ASTReader::ParseHeaderSearchOptions(const RecordData &Record,
     bool IsFramework = Record[Idx++];
     bool IgnoreSysRoot = Record[Idx++];
     bool IsInternal = Record[Idx++];
-    bool ImplicitExternC = Record[Idx++];
     HSOpts.UserEntries.push_back(
       HeaderSearchOptions::Entry(Path, Group, IsFramework, IgnoreSysRoot,
-                                 IsInternal, ImplicitExternC));
+                                 IsInternal));
   }
 
   // System header prefixes.
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index d3981533245..0499f5c6f47 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1115,7 +1115,6 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
     Record.push_back(Entry.IsFramework);
     Record.push_back(Entry.IgnoreSysRoot);
     Record.push_back(Entry.IsInternal);
-    Record.push_back(Entry.ImplicitExternC);
   }
 
   // System header prefixes.