Revert "[libunwind] Drop the dependency on <algorithm>, add placement new inline"

This reverts commit r352384: this broke on ARM as UnwindCursor.hpp
still has some C++ library dependencies.

llvm-svn: 352427
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 4ecdb70424a7c057bf6858027abc3a0f59454210
diff --git a/src/UnwindCursor.hpp b/src/UnwindCursor.hpp
index 62efe77..497ff84 100644
--- a/src/UnwindCursor.hpp
+++ b/src/UnwindCursor.hpp
@@ -11,6 +11,7 @@
 #ifndef __UNWINDCURSOR_HPP__
 #define __UNWINDCURSOR_HPP__
 
+#include <algorithm>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>