JIT64: optimize carry calculations

Omit carry calculations that get overwritten later in the block before they're
used. Very common in the case of srawix and friends.

Source/Core/Core/PowerPC/PPCAnalyst.h

@@ -33,12 +33,12 @@ struct CodeOp //16B
 	bool isBranchTarget;
 	bool wantsCR0;
 	bool wantsCR1;
-	bool wantsPS1;
 	bool wantsFPRF;
+	bool wantsCA;
 	bool outputCR0;
 	bool outputCR1;
-	bool outputPS1;
 	bool outputFPRF;
+	bool outputCA;
 	bool canEndBlock;
 	bool skip;  // followed BL-s for example
 };