[Alignment][NFC] Remove dependency on GlobalObject::setAlignment(unsigned)

Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

Reviewers: courbet

Subscribers: arsenm, mehdi_amini, jvesely, nhaehnle, hiraditya, steven_wu, dexonsmith, dang, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D68944

llvm-svn: 374880
diff --git a/llvm/lib/CodeGen/GlobalMerge.cpp b/llvm/lib/CodeGen/GlobalMerge.cpp
index 09201c2..d4fa45f 100644
--- a/llvm/lib/CodeGen/GlobalMerge.cpp
+++ b/llvm/lib/CodeGen/GlobalMerge.cpp
@@ -456,14 +456,14 @@
 
     bool HasExternal = false;
     StringRef FirstExternalName;
-    unsigned MaxAlign = 1;
+    Align MaxAlign;
     unsigned CurIdx = 0;
     for (j = i; j != -1; j = GlobalSet.find_next(j)) {
       Type *Ty = Globals[j]->getValueType();
 
       // Make sure we use the same alignment AsmPrinter would use.
-      unsigned Align = DL.getPreferredAlignment(Globals[j]);
-      unsigned Padding = alignTo(MergedSize, Align) - MergedSize;
+      Align Alignment(DL.getPreferredAlignment(Globals[j]));
+      unsigned Padding = alignTo(MergedSize, Alignment) - MergedSize;
       MergedSize += Padding;
       MergedSize += DL.getTypeAllocSize(Ty);
       if (MergedSize > MaxOffset) {
@@ -478,7 +478,7 @@
       Inits.push_back(Globals[j]->getInitializer());
       StructIdxs.push_back(CurIdx++);
 
-      MaxAlign = std::max(MaxAlign, Align);
+      MaxAlign = std::max(MaxAlign, Alignment);
 
       if (Globals[j]->hasExternalLinkage() && !HasExternal) {
         HasExternal = true;