A64: Add fast path for Fcvtas_Gp/S/V, Fcvtau_Gp/S/V and Frinta_S/V in… (#3712)

* A64: Add fast path for Fcvtas_Gp/S/V, Fcvtau_Gp/S/V and Frinta_S/V instructions;

they use "Round to Nearest with Ties to Away" rounding mode not supported in x86.

All instructions involved have been tested locally in both release and debug modes, in both lowcq and highcq.

The titles Mario Strikers and Super Smash Bros. U. use these instructions intensively.

* Update Ptc.cs

* A32: Add fast path for Vcvta_RM, Vrinta_RM and Vrinta_V instructions aswell.

ARMeilleure/State/FPRoundingMode.cs

@@ -2,9 +2,10 @@ namespace ARMeilleure.State
 {
     public enum FPRoundingMode
     {
-        ToNearest            = 0,
+        ToNearest            = 0, // With ties to even.
         TowardsPlusInfinity  = 1,
         TowardsMinusInfinity = 2,
-        TowardsZero          = 3
+        TowardsZero          = 3,
+        ToNearestAway        = 4 // With ties to away.
     }
 }