PNaCl: Fix FlattenGlobals to correctly handle implicitly-aligned variables

lib/Transforms/NaCl/FlattenGlobals.cpp

 //===- FlattenGlobals.cpp - Flatten global variable initializers-----------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This pass converts initializers for global variables into a
@@ skipping 237 matching lines @@
 
   for (Module::global_iterator I = M.global_begin(), E = M.global_end();
        I != E; ) {
     GlobalVariable *Global = I++;
     // Variables with "appending" linkage must always be arrays and so
     // cannot be normalized, so leave them alone.
     if (Global->hasAppendingLinkage())
       continue;
     Modified = true;
 
-    uint64_t Size = DL.getTypeAllocSize(
-        Global->getType()->getPointerElementType());
+    Type *GlobalType = Global->getType()->getPointerElementType();
+    uint64_t Size = DL.getTypeAllocSize(GlobalType);
     Constant *NewInit;
     Type *NewType;
     if (Global->hasInitializer()) {
       if (Global->getInitializer()->isNullValue()) {
         // As optimization, for large BSS variables, avoid allocating
         // a buffer that would only be filled with zeroes.
         NewType = ArrayType::get(I8, Size);
         NewInit = ConstantAggregateZero::get(NewType);
       } else {
         FlattenedConstant Buffer(&DL, Global->getInitializer());
         NewInit = Buffer.getAsNormalFormConstant();
         NewType = NewInit->getType();
       }
     } else {
       NewInit = NULL;
       NewType = ArrayType::get(I8, Size);
     }
     GlobalVariable *NewGlobal = new GlobalVariable(
         M, NewType,
         Global->isConstant(),
         Global->getLinkage(),
         NewInit, "", Global,
         Global->getThreadLocalMode());
     NewGlobal->copyAttributesFrom(Global);
+    if (NewGlobal->getAlignment() == 0)
+      NewGlobal->setAlignment(DL.getPrefTypeAlignment(GlobalType));
     NewGlobal->setExternallyInitialized(Global->isExternallyInitialized());
     NewGlobal->takeName(Global);
     Global->replaceAllUsesWith(
         ConstantExpr::getBitCast(NewGlobal, Global->getType()));
     Global->eraseFromParent();
   }
   return Modified;
 
 }
 
 ModulePass *llvm::createFlattenGlobalsPass() {
   return new FlattenGlobals();
 }