Rearange header order to match llvm style. This exposed some missing types.
Also fix some Platform.h includes that somehow got missed last time.

llvm-svn: 153590
diff --git a/lld/lib/Core/Resolver.cpp b/lld/lib/Core/Resolver.cpp
index 62361e0..617431e 100644
--- a/lld/lib/Core/Resolver.cpp
+++ b/lld/lib/Core/Resolver.cpp
@@ -11,15 +11,14 @@
 #include "lld/Core/Atom.h"
 #include "lld/Core/File.h"
 #include "lld/Core/InputFiles.h"
+#include "lld/Core/Platform.h"
 #include "lld/Core/SymbolTable.h"
 #include "lld/Core/UndefinedAtom.h"
-#include "lld/Platform/Platform.h"
 
 #include "llvm/Support/raw_ostream.h"
 
 #include <algorithm>
 #include <cassert>
-
 #include <vector>
 
 namespace lld {