Move solution and projects to src

src/Ryujinx.Graphics.Shader/CodeGen/Glsl/HelperFunctions/ShuffleDown.glsl

@@ -0,0 +1,11 @@
+float Helper_ShuffleDown(float x, uint index, uint mask, out bool valid)
+{
+    uint clamp = mask & 0x1fu;
+    uint segMask = (mask >> 8) & 0x1fu;
+    uint minThreadId = $SUBGROUP_INVOCATION$ & segMask;
+    uint maxThreadId = minThreadId | (clamp & ~segMask);
+    uint srcThreadId = $SUBGROUP_INVOCATION$ + index;
+    valid = srcThreadId <= maxThreadId;
+    float v = $SUBGROUP_BROADCAST$(x, srcThreadId);
+    return valid ? v : x;
+}