[Physics] Remove unused enum and previous namespace import for inlining

sources/core/Xenko.Core.Mathematics/Matrix.cs

@@ -32,7 +32,6 @@
 using System;
 using System.Globalization;
 using System.Runtime.InteropServices;
-using System.Runtime.CompilerServices;
 
 namespace Xenko.Core.Mathematics
 {

sources/core/Xenko.Core.Mathematics/Quaternion.cs

@@ -28,7 +28,6 @@
 */
 using System;
 using System.Globalization;
-using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 namespace Xenko.Core.Mathematics

sources/core/Xenko.Core.Mathematics/Vector3.cs

@@ -27,7 +27,6 @@
 * THE SOFTWARE.
 */
 using System;
-using System.ComponentModel;
 using System.Globalization;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;

sources/engine/Xenko.Physics/Shapes/HeightfieldColliderShape.cs

@@ -144,16 +144,6 @@ public override void Dispose()
             FloatArray = null;
         }
 
-        private enum BulletPhyScalarType
-        {
-            PhyFloat = BulletSharp.PhyScalarType.Single,
-            PhyDouble = BulletSharp.PhyScalarType.Double,
-            PhyInteger = BulletSharp.PhyScalarType.Int32,
-            PhyShort = BulletSharp.PhyScalarType.Int16,
-            PhyFixedpoint88 = BulletSharp.PhyScalarType.FixedPoint88,
-            PhyUchar = BulletSharp.PhyScalarType.Byte,
-        }
-
         public class HeightfieldDebugPrimitive : IDebugPrimitive
         {
             private static readonly int MaxTileWidth = 64;