Teach GlobalOpt to delete aliases with internal linkage (after

forwarding any uses).  GlobalDCE can also do this, but is only
run at -O3.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90850 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/GlobalOpt/2009-02-15-ResolveAlias.ll

@@ -1,6 +1,8 @@
-; RUN: opt < %s -globalopt -S | grep {define void @a}
+; RUN: opt < %s -globalopt -S | FileCheck %s
 
 define internal void @f() {
+; CHECK-NOT: @f
+; CHECK: define void @a
 	ret void
 }
 
@@ -10,3 +12,13 @@ define void @g() {
 	call void()* @a()
 	ret void
 }
+
+@b = alias internal void ()* @g
+; CHECK-NOT: @b
+
+define void @h() {
+	call void()* @b()
+; CHECK: call void @g
+	ret void
+}
+