[opaque pointer type] Pass GlobalAlias the actual pointer type rather than decomposing it into pointee type + address space

Many of the callers already have the pointer type anyway, and for the
couple of callers that don't it's pretty easy to call PointerType::get
on the pointee type and address space.

This avoids LLParser from using PointerType::getElementType when parsing
GlobalAliases from IR.

llvm-svn: 236160
diff --git a/llvm/lib/Transforms/IPO/LowerBitSets.cpp b/llvm/lib/Transforms/IPO/LowerBitSets.cpp
index f3f8529..bffeebb 100644
--- a/llvm/lib/Transforms/IPO/LowerBitSets.cpp
+++ b/llvm/lib/Transforms/IPO/LowerBitSets.cpp
@@ -358,8 +358,9 @@
     if (LinkerSubsectionsViaSymbols) {
       BAI->ByteArray->replaceAllUsesWith(GEP);
     } else {
-      GlobalAlias *Alias = GlobalAlias::create(
-          Int8Ty, 0, GlobalValue::PrivateLinkage, "bits", GEP, M);
+      GlobalAlias *Alias =
+          GlobalAlias::create(PointerType::getUnqual(Int8Ty),
+                              GlobalValue::PrivateLinkage, "bits", GEP, M);
       BAI->ByteArray->replaceAllUsesWith(Alias);
     }
     BAI->ByteArray->eraseFromParent();
@@ -401,7 +402,7 @@
       // Each use of the byte array uses a different alias. This makes the
       // backend less likely to reuse previously computed byte array addresses,
       // improving the security of the CFI mechanism based on this pass.
-      ByteArray = GlobalAlias::create(BAI->ByteArray->getValueType(), 0,
+      ByteArray = GlobalAlias::create(BAI->ByteArray->getType(),
                                       GlobalValue::PrivateLinkage, "bits_use",
                                       ByteArray, M);
     }
@@ -553,10 +554,9 @@
     if (LinkerSubsectionsViaSymbols) {
       Globals[I]->replaceAllUsesWith(CombinedGlobalElemPtr);
     } else {
-      GlobalAlias *GAlias = GlobalAlias::create(
-          Globals[I]->getType()->getElementType(),
-          Globals[I]->getType()->getAddressSpace(), Globals[I]->getLinkage(),
-          "", CombinedGlobalElemPtr, M);
+      GlobalAlias *GAlias =
+          GlobalAlias::create(Globals[I]->getType(), Globals[I]->getLinkage(),
+                              "", CombinedGlobalElemPtr, M);
       GAlias->takeName(Globals[I]);
       Globals[I]->replaceAllUsesWith(GAlias);
     }