parseFnProto

    pub fn parseFnProto(p: *Parser) Error!bool {
        const def_index = @backingInt(Def.defFnProto);
        if (p.depths[def_index] > max_depth) return error.MaxDepth;
        p.depths[def_index] += 1;
        defer p.depths[def_index] -= 1;
        return blk_0: {
            const pos_0 = p.i;
            if (try p.parseKEYWORD_fn() and (try p.parseIDENTIFIER() or true) and try p.parseParamDeclList() and (try p.parseByteAlign() or true) and (try p.parseAddrSpace() or true) and (try p.parseLinkSection() or true) and (try p.parseCallConv() or true) and (try p.parseEXCLAMATIONMARK() or true) and try p.parseTypeExpr()) break :blk_0 true;
            p.i = pos_0;
            break :blk_0 false;
        };
    }