Revert "Don't block quick callee saved registers for optimizing."

X64 has one libcore test failing, and codegen_test on
arm is failing.

This reverts commit 6004796d6c630696127df2494dcd4f30d1367a34.

Change-Id: I20e00431fa18e11ce4c0cb6fffa91977fa8e9b4f
diff --git a/compiler/utils/x86/assembler_x86.cc b/compiler/utils/x86/assembler_x86.cc
index 6aec45e..f0353f6 100644
--- a/compiler/utils/x86/assembler_x86.cc
+++ b/compiler/utils/x86/assembler_x86.cc
@@ -269,11 +269,11 @@
 }
 
 
-void X86Assembler::setb(Condition condition, ByteRegister dst) {
+void X86Assembler::setb(Condition condition, Register dst) {
   AssemblerBuffer::EnsureCapacity ensured(&buffer_);
   EmitUint8(0x0F);
   EmitUint8(0x90 + condition);
-  EmitRegisterOperand(0, dst);
+  EmitOperand(0, Operand(dst));
 }