Change the GlobalAlias constructor to look a bit more like GlobalVariable.

This is part of the fix for pr10367. A GlobalAlias always has a pointer type,
so just have the constructor build the type.

llvm-svn: 208983
diff --git a/llvm/lib/IR/Core.cpp b/llvm/lib/IR/Core.cpp
index 81d137e..40c1c70 100644
--- a/llvm/lib/IR/Core.cpp
+++ b/llvm/lib/IR/Core.cpp
@@ -1488,8 +1488,10 @@
 
 LLVMValueRef LLVMAddAlias(LLVMModuleRef M, LLVMTypeRef Ty, LLVMValueRef Aliasee,
                           const char *Name) {
-  return wrap(new GlobalAlias(unwrap(Ty), GlobalValue::ExternalLinkage, Name,
-                              unwrap<Constant>(Aliasee), unwrap (M)));
+  auto *PTy = cast<PointerType>(unwrap(Ty));
+  return wrap(new GlobalAlias(
+      PTy->getElementType(), GlobalValue::ExternalLinkage, Name,
+      unwrap<Constant>(Aliasee), unwrap(M), PTy->getAddressSpace()));
 }
 
 /*--.. Operations on functions .............................................--*/