glsl: Increase NUM_VARS that can be allocated

needed for HW:AoC.

src/shader_recompiler/backend/glsl/var_alloc.h

@@ -57,7 +57,7 @@ static_assert(sizeof(Id) == sizeof(u32));
 
 class VarAlloc {
 public:
-    static constexpr size_t NUM_VARS = 511;
+    static constexpr size_t NUM_VARS = 1023;
     struct UseTracker {
         size_t num_used{};
         std::bitset<NUM_VARS> var_use{};