fix(simulator): support array literal function arguments

[tignear]

Expand array literals using the formal function argument type before converting their elements into simulator expressions. Previously, passing an array literal directly to a function caused the simulator to panic with unhandled Expression variant.

function pick (
    x: input logic<4> [2],
) -> logic<4> {
    return x[1];
}

always_ff (clk) {
    out_q = pick('{in_hi, in_lo});
}

The added tests cover unpacked, packed, single-element, repeated, default-filled, and multidimensional literals, including nested function calls.

[codspeed-hq]

Merging this PR will not alter performance

✅ 8 untouched benchmarks

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_{Comparing tignear:fix/simulator-array-literal-function-args (a099902) with master (3c02060)}

[tignear]

I found that malformed array literal arguments bypass the analyzer. This PR avoids the existing panic, but reports only a generic unsupported description error. I’m converting it back to draft while I fix the diagnostics. Sorry I missed this.