Remove some old debris

GPU/Common/SoftwareTransformCommon.cpp

@@ -558,7 +558,7 @@ void SoftwareTransform::CalcCullParams(float &minZValue, float &maxZValue) const
 	maxZValue = 1.000030517578125f * gstate_c.vpDepthScale;
 	minZValue = -maxZValue;
 	// Scale and offset the Z appropriately, since we baked that into a projection transform.
-	if (params_.usesHalfZ) {
+	if (true) {  // all backends are "use half z" now
 		maxZValue = maxZValue * 0.5f + 0.5f + gstate_c.vpZOffset * 0.5f;
 		minZValue = minZValue * 0.5f + 0.5f + gstate_c.vpZOffset * 0.5f;
 	} else {

GPU/Common/SoftwareTransformCommon.h

@@ -58,8 +58,6 @@ struct SoftwareTransformParams {
 	TextureCacheCommon *texCache;
 	bool allowClear;
 	bool allowSeparateAlphaClear;
-	bool flippedY;
-	bool usesHalfZ;
 };
 
 // Converts an index buffer to make the provoking vertex the last.

GPU/D3D11/DrawEngineD3D11.cpp

@@ -406,8 +406,6 @@ void DrawEngineD3D11::Flush() {
 		params.texCache = textureCache_;
 		params.allowClear = true;
 		params.allowSeparateAlphaClear = false;  // D3D11 doesn't support separate alpha clears
-		params.flippedY = false;
-		params.usesHalfZ = true;
 
 		if (gstate.getShadeMode() == GE_SHADE_FLAT) {
 			// We need to rotate the index buffer to simulate a different provoking vertex.

GPU/GLES/DrawEngineGLES.cpp

@@ -351,8 +351,6 @@ void DrawEngineGLES::Flush() {
 		params.texCache = textureCache_;
 		params.allowClear = true;  // Clear in OpenGL respects scissor rects, so we'll use it.
 		params.allowSeparateAlphaClear = true;
-		params.flippedY = framebufferManager_->UseBufferedRendering();
-		params.usesHalfZ = false;
 
 		// We need correct viewport values in gstate_c already.
 		if (gstate_c.IsDirty(DIRTY_VIEWPORTSCISSOR_STATE)) {

GPU/Vulkan/DrawEngineVulkan.cpp

@@ -420,8 +420,6 @@ void DrawEngineVulkan::Flush() {
 				IndexBufferProvokingLastToFirst(prim, inds, vertexCount);
 			}
 		}
-		params.flippedY = true;
-		params.usesHalfZ = true;
 
 		// We need to update the viewport early because it's checked for flipping in SoftwareTransform.
 		// We don't have a "DrawStateEarly" in vulkan, so...