WIP: HLSL: add f16tof32 and f32tof16 decompositions.

Test/hlsl.intrinsics.f3216.frag

@@ -0,0 +1,29 @@
+uint PixelShaderFunctionS(float inF0)
+{
+    return f32tof16(inF0);
+}
+
+uint1 PixelShaderFunction1(float1 inF0)
+{
+    return f32tof16(inF0);
+}
+
+uint2 PixelShaderFunction2(float2 inF0)
+{
+    return f32tof16(inF0);
+}
+
+uint3 PixelShaderFunction3(float3 inF0)
+{
+    return f32tof16(inF0);
+}
+
+uint4 PixelShaderFunction(float4 inF0)
+{
+    return f32tof16(inF0);
+}
+
+float4 main() : SV_Target0
+{
+    return 0;
+}