Add Sema implementation of #pragma pack stack. 
 - Follows the MSVC (original) implementation, including support of
   pack(show) (useful for testing).
 - Implements support for named pack records which gcc seems to
   ignore (or implements incorrectly).
 - Not currently wired to anything, only functionality change is the
   type checking of the pragma.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@57476 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index 80ce2cc..2113417 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -82,7 +82,7 @@
 
 Sema::Sema(Preprocessor &pp, ASTContext &ctxt, ASTConsumer &consumer)
   : PP(pp), Context(ctxt), Consumer(consumer), CurContext(0), CurBlock(0),
-    IdResolver(pp.getLangOptions()) {
+    PackContext(0), IdResolver(pp.getLangOptions()) {
   
   // Get IdentifierInfo objects for known functions for which we
   // do extra checking.