JitArm64_Integer: addex - Optimize InHostCarry for -1

Same thing we did for subfex.

Before:
0x1280001a   mov    w26, #-0x1                ; =-1
0x1a1f035a   adc    w26, w26, wzr

After:
0x5a9f23fa   csetm  w26, lo

Source/Core/Core/PowerPC/JitArm64/JitArm64_Integer.cpp

@@ -1500,6 +1500,13 @@ void JitArm64::addex(UGeckoInstruction inst)
         // RD = 0 + carry = carry ? 1 : 0
         CSET(RD, CC_CS);
       }
+      else if (is_all_ones)
+      {
+        // RD = -1 + carry = carry ? 0 : -1
+        // Note that CSETM sets the destination to -1 if the condition is true,
+        // and 0 otherwise. Hence, the condition must be carry clear.
+        CSETM(RD, CC_CC);
+      }
       else
       {
         MOVI2R(RD, imm);