Reorder includes in Target backends to following coding standards. Remove some superfluous forward declarations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152997 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Mips/MipsISelLowering.h b/lib/Target/Mips/MipsISelLowering.h
index 82d4c71..66f45cd 100644
--- a/lib/Target/Mips/MipsISelLowering.h
+++ b/lib/Target/Mips/MipsISelLowering.h
@@ -15,10 +15,10 @@
 #ifndef MipsISELLOWERING_H
 #define MipsISELLOWERING_H
 
-#include "llvm/CodeGen/SelectionDAG.h"
-#include "llvm/Target/TargetLowering.h"
 #include "Mips.h"
 #include "MipsSubtarget.h"
+#include "llvm/CodeGen/SelectionDAG.h"
+#include "llvm/Target/TargetLowering.h"
 
 namespace llvm {
   namespace MipsISD {