Use a new approach for shader BRX targets (#2532)

* Use a new approach for shader BRX targets

* Make shader cache actually work

* Improve the shader pattern matching a bit

* Extend LDC search to predecessor blocks, catches more cases

* Nit

* Only save the amount of constant buffer data actually used. Avoids crashes on partially mapped buffers

* Ignore Rd on predicate instructions, as they do not have a Rd register (catches more cases)

Ryujinx.Graphics.Shader/IGpuAccessor.cs

@@ -7,6 +7,11 @@
             // No default log output.
         }
 
+        uint ConstantBuffer1Read(int offset)
+        {
+            return 0;
+        }
+
         T MemoryRead<T>(ulong address) where T : unmanaged;
 
         bool MemoryMapped(ulong address)