Revert r309106 "Recommit r308327 2nd time: Add a warning for missing"

The warning fires on non-suspicious code in Chromium. Reverting until a
solution is figured out.

> Recommit r308327 2nd time: Add a warning for missing
> '#pragma pack (pop)' and suspicious uses of '#pragma pack' in included files
>
> The first recommit (r308441) caused a "non-default #pragma pack value might
> change the alignment of struct or union members in the included file" warning
> in LLVM itself. This recommit tweaks the added warning to avoid warnings for
> #includes that don't have any records that are affected by the non-default
> alignment. This tweak avoids the previously emitted warning in LLVM.
>
> Original message:
>
> This commit adds a new -Wpragma-pack warning. It warns in the following cases:
>
> - When a translation unit is missing terminating #pragma pack (pop) directives.
> - When entering an included file if the current alignment value as determined
>   by '#pragma pack' directives is different from the default alignment value.
> - When leaving an included file that changed the state of the current alignment
>   value.
>
> rdar://10184173
>
> Differential Revision: https://reviews.llvm.org/D35484

llvm-svn: 309186
diff --git a/clang/lib/Parse/ParsePragma.cpp b/clang/lib/Parse/ParsePragma.cpp
index c5215ff..2627437 100644
--- a/clang/lib/Parse/ParsePragma.cpp
+++ b/clang/lib/Parse/ParsePragma.cpp
@@ -422,20 +422,15 @@
   assert(Tok.is(tok::annot_pragma_pack));
   PragmaPackInfo *Info =
     static_cast<PragmaPackInfo *>(Tok.getAnnotationValue());
-  SourceLocation PragmaLoc = Tok.getLocation();
+  SourceLocation PragmaLoc = ConsumeAnnotationToken();
   ExprResult Alignment;
   if (Info->Alignment.is(tok::numeric_constant)) {
     Alignment = Actions.ActOnNumericConstant(Info->Alignment);
-    if (Alignment.isInvalid()) {
-      ConsumeAnnotationToken();
+    if (Alignment.isInvalid())
       return;
-    }
   }
   Actions.ActOnPragmaPack(PragmaLoc, Info->Action, Info->SlotLabel,
                           Alignment.get());
-  // Consume the token after processing the pragma to enable pragma-specific
-  // #include warnings.
-  ConsumeAnnotationToken();
 }
 
 void Parser::HandlePragmaMSStruct() {