HLSL: pass tessellation execution modes through to SPIR-V

The SPIR-V generator had assumed tessellation modes such as
primitive type and vertex order would only appear in tess eval
(domain) shaders.  SPIR-V allows either, and HLSL allows and
possibly requires them to be in the hull shader.

This change:

1. Passes them through for either tessellation stage, and,

2. Does not set up defaults in the domain stage for HLSl compilation,
to avoid conflicting definitions.

Test/hlsl.domain.1.tese

@@ -0,0 +1,32 @@
+
+struct ds_in_t 
+{ 
+    float4 pos  : POSITION; 
+    float3 norm : TEXCOORD0; 
+}; 
+
+struct pcf_in_t 
+{ 
+    float flTessFactor [3]   : SV_TessFactor; 
+    float flInsideTessFactor : SV_InsideTessFactor; 
+}; 
+
+struct gs_in_t 
+{ 
+    float4 pos  : POSITION; 
+    float3 norm : TEXCOORD0; 
+}; 
+
+[domain ( "tri" )] 
+gs_in_t main (const OutputPatch <ds_in_t, 3> i, float3 tesscoord : SV_DomainLocation, pcf_in_t pcf_data ) 
+{ 
+    gs_in_t o; 
+
+    o.pos  = i[0].pos + tesscoord.x;
+    o.norm = i[0].norm + tesscoord.y;
+
+    tesscoord.z;
+    
+    return o; 
+}
+