Replace Shader,VertexShader,PixelShader with SpirvShader

Also deletes tons of fixed-function-centric stuff that will never be
used by the Vulkan backend. Very little of the SPIRV integration
actually does anything interesting yet (we don't generate code) but this
wires on the new shader representation.

Bug: b/120799499

Change-Id: Ib76e2086113098aebd526a0da461689d4344e8c2
Reviewed-on: https://swiftshader-review.googlesource.com/c/23090
Tested-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
diff --git a/src/Device/Context.cpp b/src/Device/Context.cpp
index 9e5835a..6f12455 100644
--- a/src/Device/Context.cpp
+++ b/src/Device/Context.cpp
@@ -16,10 +16,9 @@
 
 #include "Primitive.hpp"
 #include "Surface.hpp"
-#include "Pipeline/PixelShader.hpp"
-#include "Pipeline/VertexShader.hpp"
 #include "System/Memory.hpp"
 #include "Vulkan/VkDebug.hpp"
+#include "Pipeline/SpirvShader.hpp"
 
 #include <string.h>
 
@@ -27,7 +26,6 @@
 {
 	extern bool perspectiveCorrection;
 
-	bool halfIntegerCoordinates = false;     // Pixel centers are not at integer coordinates
 	bool booleanFaceRegister = false;
 	bool fullPixelPositionRegister = false;
 	bool leadingVertexFirst = false;         // Flat shading uses first vertex, else last
@@ -724,16 +722,6 @@
 		return true;
 	}
 
-	unsigned short Context::pixelShaderModel() const
-	{
-		return pixelShader ? pixelShader->getShaderModel() : 0x0000;
-	}
-
-	unsigned short Context::vertexShaderModel() const
-	{
-		return vertexShader ? vertexShader->getShaderModel() : 0x0000;
-	}
-
 	int Context::getMultiSampleCount() const
 	{
 		return renderTarget[0] ? renderTarget[0]->getMultiSampleCount() : 1;
@@ -774,6 +762,6 @@
 
 	bool Context::colorUsed()
 	{
-		return colorWriteActive() || alphaTestActive() || (pixelShader && pixelShader->containsKill());
+		return colorWriteActive() || alphaTestActive() || (pixelShader && pixelShader->getModes().ContainsKill);
 	}
 }