Subzero: Refactor x86 register representation to actively use aliases.

src/IceRegistersMIPS32.h

Index: src/IceRegistersMIPS32.h
diff --git a/src/IceRegistersMIPS32.h b/src/IceRegistersMIPS32.h
index df13f0e6ea635ebbcbc0dc878ecacab7f56ec71a..38335f89e2bfa9d7a3fc585630d3237649474a22 100644
--- a/src/IceRegistersMIPS32.h
+++ b/src/IceRegistersMIPS32.h
@@ -17,6 +17,7 @@
 
 #include "IceDefs.h"
 #include "IceInstMIPS32.def"
+#include "IceOperand.h" // RC_Target
 #include "IceTypes.h"
 
 namespace Ice {
@@ -59,6 +60,9 @@ static inline GPRRegister getEncodedGPR(int32_t RegNum) {
 
 } // end of namespace RegMIPS32
 
+// Extend enum RegClass with MIPS32-specific register classes (if any).
+enum RegClassMIPS32 : uint8_t { RCMIPS32_NUM = RC_Target };
+
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEREGISTERSMIPS32_H