gl_shader_decompiler: Implement MOV_C.

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -664,6 +664,11 @@ private:
             }
 
             switch (opcode->GetId()) {
+            case OpCode::Id::MOV_C: {
+                regs.SetRegisterToFloat(instr.gpr0, 0, op_b, 1, 1);
+                break;
+            }
+
             case OpCode::Id::MOV32_IMM: {
                 // mov32i doesn't have abs or neg bits.
                 regs.SetRegisterToFloat(instr.gpr0, 0, GetImmediate32(instr), 1, 1);