Implement [dcl.align]p5 and C11 6.7.5/4: alignas cannot underalign.
Also support alignas(0), which C++11 and C11 require us to ignore.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174157 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index c146e9d..2d3d0bd 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -347,6 +347,9 @@
   }
   SemaRef.InstantiateAttrs(TemplateArgs, D, Var, LateAttrs, StartingScope);
 
+  if (Var->hasAttrs())
+    SemaRef.CheckAlignasUnderalignment(Var);
+
   // Link instantiations of static data members back to the template from
   // which they were instantiated.
   if (Var->isStaticDataMember())
@@ -459,6 +462,9 @@
 
   SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope);
 
+  if (Field->hasAttrs())
+    SemaRef.CheckAlignasUnderalignment(Field);
+
   if (Invalid)
     Field->setInvalidDecl();