Teach the AST reader and writer to preserve the __DEPRECATED bit in
language options, and warn when reading an AST with a different value
for the bit.

There doesn't appear to be a good way to test this (commenting out
similar other language options doesn't break anything) but if folks have
suggestions on tests I'm happy to add them.

llvm-svn: 130071
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index dafce43..3525c70 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -129,6 +129,7 @@
   PARSE_LANGOPT_IMPORTANT(PICLevel, diag::warn_pch_pic_level);
   PARSE_LANGOPT_IMPORTANT(GNUInline, diag::warn_pch_gnu_inline);
   PARSE_LANGOPT_IMPORTANT(NoInline, diag::warn_pch_no_inline);
+  PARSE_LANGOPT_IMPORTANT(Deprecated, diag::warn_pch_deprecated);
   PARSE_LANGOPT_IMPORTANT(AccessControl, diag::warn_pch_access_control);
   PARSE_LANGOPT_IMPORTANT(CharIsSigned, diag::warn_pch_char_signed);
   PARSE_LANGOPT_IMPORTANT(ShortWChar, diag::warn_pch_short_wchar);
@@ -2838,6 +2839,7 @@
     PARSE_LANGOPT(PICLevel);
     PARSE_LANGOPT(GNUInline);
     PARSE_LANGOPT(NoInline);
+    PARSE_LANGOPT(Deprecated);
     PARSE_LANGOPT(AccessControl);
     PARSE_LANGOPT(CharIsSigned);
     PARSE_LANGOPT(ShortWChar);