[MSVC] Implementation of __unaligned as a proper type qualifier

This patch implements __unaligned (MS extension) as a proper type qualifier
(before that, it was implemented as an ignored attribute).

It also fixes PR27367 and PR27666.

Differential Revision: http://reviews.llvm.org/D20103

llvm-svn: 269220
diff --git a/clang/lib/Parse/ParseTentative.cpp b/clang/lib/Parse/ParseTentative.cpp
index 4d4bd80..cde5581 100644
--- a/clang/lib/Parse/ParseTentative.cpp
+++ b/clang/lib/Parse/ParseTentative.cpp
@@ -833,7 +833,7 @@
       // '(' abstract-declarator ')'
       if (Tok.isOneOf(tok::kw___attribute, tok::kw___declspec, tok::kw___cdecl,
                       tok::kw___stdcall, tok::kw___fastcall, tok::kw___thiscall,
-                      tok::kw___vectorcall, tok::kw___unaligned))
+                      tok::kw___vectorcall))
         return TPResult::True; // attributes indicate declaration
       TPResult TPR = TryParseDeclarator(mayBeAbstract, mayHaveIdentifier);
       if (TPR != TPResult::Ambiguous)