Description:

Existential values nested inside structs, tuples, or arrays should work correctly when:

Loaded from buffers
Passed between dynamically dispatched functions

Test Cases:

interface IFoo { float eval(); }

struct Container {
IFoo item; // Existential in struct field
int metadata;
}

struct ArrayContainer {
IFoo[4] items; // Array of existentials
}

// Buffer containing existentials
StructuredBuffer gContainers;

void test() {
// Load from buffer
Container c = gContainers[0];
float val = c.item.eval(); // Dispatch from buffer-loaded existential

// Pass between functions
process(c);

}

void process(Container c) {
c.item.eval(); // Should still dispatch correctly
}

// Dynamically dispatched function receiving nested existential
interface IProcessor {
void process(Container c); // Container has IFoo field
}

Expected Behavior:

Buffer loads correctly reconstruct existential representation (tag + value)
Passing through functions preserves dispatch capability
Notes:

Memory layout in buffers must match existential tuple format
Need to handle alignment of nested existentials