ART: Include cleanup

Let clang-format reorder the header includes.

Derived with:

* .clang-format:
 BasedOnStyle: Google
 IncludeIsMainRegex: '(_test|-inl)?$'

* Steps:
 find . -name '*.cc' -o -name '*.h' | xargs sed -i.bak -e 's/^#include/ #include/' ; git commit -a -m 'ART: Include cleanup'
 git-clang-format -style=file HEAD^
 manual inspection
 git commit -a --amend

Test: mmma art
Change-Id: Ia963a8ce3ce5f96b5e78acd587e26908c7a70d02
diff --git a/compiler/linker/vector_output_stream.h b/compiler/linker/vector_output_stream.h
index 3210143..a9b93e7 100644
--- a/compiler/linker/vector_output_stream.h
+++ b/compiler/linker/vector_output_stream.h
@@ -19,8 +19,8 @@
 
 #include "output_stream.h"
 
-#include <string>
 #include <string.h>
+#include <string>
 #include <vector>
 
 namespace art {