Revert "[opaque pointer type] update for LLVM API change"

This was the wrong direction to take anyway (because ultimately the
GlobalValue needed the pointee type again and /it/ used
PointerType::getElementType eventually anyway)... let's go a different way.

This reverts commit r236161.

llvm-svn: 247586
diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index a981dd6..172ddda 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -1734,8 +1734,9 @@
         C->setSelectionKind(llvm::Comdat::Largest);
     }
     VFTable = llvm::GlobalAlias::create(
-        cast<llvm::PointerType>(VTableGEP->getType()), VFTableLinkage,
-        VFTableName.str(), VTableGEP, &CGM.getModule());
+        cast<llvm::SequentialType>(VTableGEP->getType())->getElementType(),
+        /*AddressSpace=*/0, VFTableLinkage, VFTableName.str(), VTableGEP,
+        &CGM.getModule());
     VFTable->setUnnamedAddr(true);
   } else {
     // We don't need a GlobalAlias to be a symbol for the VTable if we won't