[dxbc] Use NClamp for tess factors and depth clamp

This flushes NaN tess factors to 0, which should match D3D behaviour
for both outer and inner tess factors. The legacy code hasn't been
touched in 7 years.

src/dxbc/dxbc_compiler.cpp

@@ -6109,7 +6109,7 @@ namespace dxvk {
 
       DxbcRegisterValue value = emitValueLoad(ptr);
 
-      value.id = m_module.opFClamp(
+      value.id = m_module.opNClamp(
         getVectorTypeId(ptr.type),
         value.id,
         m_module.constf32(0.0f),
@@ -6566,7 +6566,7 @@ namespace dxvk {
       }
 
       DxbcRegisterValue tessValue = emitRegisterExtract(value, mask);
-      tessValue.id = m_module.opFClamp(getVectorTypeId(tessValue.type),
+      tessValue.id = m_module.opNClamp(getVectorTypeId(tessValue.type),
         tessValue.id, m_module.constf32(0.0f),
         m_module.constf32(maxTessFactor));