}

// boundsCheck generates bounds checking code. Checks if 0 <= idx <[=] len, branches to exit if not.
// Starts a new block on return.
// On input, len must be converted to full int width and be nonnegative.
// Returns idx converted to full int width.
// If bounded is true then caller guarantees the index is not out of bounds
// (but boundsCheck will still extend the index to full int width).