Subzero: Refactor x86 register definitions to use the alias mechanism.

src/IceAssemblerX86BaseImpl.h

Index: src/IceAssemblerX86BaseImpl.h
diff --git a/src/IceAssemblerX86BaseImpl.h b/src/IceAssemblerX86BaseImpl.h
index 9bdc449ff1faf3d05fbf7036eaa2473b8abe9861..acb44d2a86db795658c26f7eaa19b7134ff83299 100644
--- a/src/IceAssemblerX86BaseImpl.h
+++ b/src/IceAssemblerX86BaseImpl.h
@@ -177,7 +177,7 @@ void AssemblerX86Base<Machine>::popal() {
 
 template <class Machine>
 void AssemblerX86Base<Machine>::setcc(typename Traits::Cond::BrCond condition,
-                                      typename Traits::ByteRegister dst) {
+                                      typename Traits::GPRRegister dst) {
   AssemblerBuffer::EnsureCapacity ensured(&Buffer);
   emitRexB(IceType_i8, dst);
   emitUint8(0x0F);