Fix Fcvtl_V and Fcvtn_V; fix half to float conv. and add float to half conv. (full FP emu.). Add 4 FP Tests. (#468)

* Update CpuTest.cs

* Update CpuTestSimd.cs

* Superseded.

* Update AInstEmitSimdCvt.cs

* Update ASoftFloat.cs

* Nit.

* Update PackageReferences.

* Update AInstEmitSimdArithmetic.cs

* Update AVectorHelper.cs

* Update ASoftFloat.cs

* Update ASoftFallback.cs

* Update AThreadState.cs

* Create FPType.cs

* Create FPExc.cs

* Create FPCR.cs

* Create FPSR.cs

* Update ARoundMode.cs

* Update APState.cs

* Avoid an unwanted implicit cast of the operator >= to long, continuing to check for negative values. Remove a leftover.

* Nits.

Ryujinx.Tests/Ryujinx.Tests.csproj

@@ -16,8 +16,8 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.8.0" />
-    <PackageReference Include="NUnit" Version="3.10.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
+    <PackageReference Include="NUnit" Version="3.11.0" />
     <PackageReference Include="NUnit3TestAdapter" Version="3.10.0" />
     <PackageReference Include="System.Runtime.Intrinsics.Experimental" Version="4.5.0-rc1" />
   </ItemGroup>