Preliminary changes to allow mips target to build.

It compiles, but it doesn't work yet.

Change-Id: I2973a03bd956d8d398b9cfd1047e66fbf3ff439c
diff --git a/src/oat/utils/managed_register.h b/src/oat/utils/managed_register.h
index c0fbd21..a3d5795 100644
--- a/src/oat/utils/managed_register.h
+++ b/src/oat/utils/managed_register.h
@@ -19,12 +19,15 @@
 
 namespace art {
 
-namespace x86 {
-class X86ManagedRegister;
-}
 namespace arm {
 class ArmManagedRegister;
 }
+namespace mips {
+class MipsManagedRegister;
+}
+namespace x86 {
+class X86ManagedRegister;
+}
 
 class ManagedRegister {
  public:
@@ -38,8 +41,9 @@
     return *this;
   }
 
-  x86::X86ManagedRegister AsX86() const;
   arm::ArmManagedRegister AsArm() const;
+  mips::MipsManagedRegister AsMips() const;
+  x86::X86ManagedRegister AsX86() const;
 
   // It is valid to invoke Equals on and with a NoRegister.
   bool Equals(const ManagedRegister& other) const {