Don't eliminate memcpy's when the address of the pointer may itself be relevant. Fixes PR18304. Patch by David Wiberg!

llvm-svn: 212970
diff --git a/llvm/test/Transforms/MemCpyOpt/loadstore-sret.ll b/llvm/test/Transforms/MemCpyOpt/loadstore-sret.ll
index 89eabca..d4a700d 100644
--- a/llvm/test/Transforms/MemCpyOpt/loadstore-sret.ll
+++ b/llvm/test/Transforms/MemCpyOpt/loadstore-sret.ll
@@ -22,4 +22,4 @@
   ret void
 }
 
-declare void @_Z3barv(%"class.std::auto_ptr"* sret)
+declare void @_Z3barv(%"class.std::auto_ptr"* nocapture sret)