Work around an obnoxious GCC warning by changing semantics in a hopefully-
harmless way.

llvm-svn: 108295
diff --git a/clang/lib/CodeGen/CGException.cpp b/clang/lib/CodeGen/CGException.cpp
index bfe00ea..4980aad 100644
--- a/clang/lib/CodeGen/CGException.cpp
+++ b/clang/lib/CodeGen/CGException.cpp
@@ -1541,4 +1541,6 @@
   CGF.Builder.restoreIP(SavedIP);
 }
 
-void EHScopeStack::LazyCleanup::_anchor() {}
+EHScopeStack::LazyCleanup::~LazyCleanup() {
+  llvm_unreachable("LazyCleanup is indestructable");
+}