Constant MATCH_INT_LITERAL 

pub const MATCH_INT_LITERAL: u8 = 0x7F;

Fused match n { LIT -> ...; _ -> ... } arm test: peek the top of stack (subject left in place by the surrounding compile_match), if its Int value equals the inline imm literal — fall through to the arm body; otherwise skip via fail_offset. Replaces the DUP + LOAD_CONST + EQ + JUMP_IF_FALSE sequence the generic compile_pattern emits — one dispatch instead of four in the hot path of every match n { 0 -> ... } shape.

Encoding: MATCH_INT_LITERAL imm:i64 fail_offset:i16.