HLSL: Move frexp() to a separate test file.

Test/hlsl.intrinsic.frexp.frag

@@ -0,0 +1,37 @@
+
+float PixelShaderFunctionS(float inF0, float inF1)
+{
+    float r000 = frexp(inF0, inF1);
+    return 0.0;
+}
+
+float2 PixelShaderFunction2(float2 inF0, float2 inF1)
+{
+    float2 r000 = frexp(inF0, inF1);
+    return float2(1,2);
+}
+
+float3 PixelShaderFunction3(float3 inF0, float3 inF1)
+{
+    float3 r000 = frexp(inF0, inF1);
+    return float3(1,2,3);
+}
+
+float4 PixelShaderFunction(float4 inF0, float4 inF1)
+{
+    float4 r000 = frexp(inF0, inF1);
+    return float4(1,2,3,4);
+}
+
+// TODO: FXC doesn't accept this with (), but glslang doesn't accept it without.
+#define MATFNS(MT)                          \
+    MT r000 = frexp(inF0, inF1);
+
+struct PS_OUTPUT { float4 color : SV_Target0; };
+
+PS_OUTPUT main()
+{
+    PS_OUTPUT ps_output;
+    ps_output.color = 1.0;
+    return ps_output;
+};