SEGV in mjs_parse_ffi_signature

[Wayne-Bai]

==23415==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x0000005088c2 bp 0x7ffc50c52570 sp 0x7ffc50c52400 T0)
==23415==The signal is caused by a READ memory access.
==23415==Hint: address points to the zero page.
    #0 0x5088c2 in mjs_parse_ffi_signature /home/eval/Desktop/mjs-issues-57/mjs.c:9695:21
    #1 0x5034ba in mjs_ffi_call /home/eval/Desktop/mjs-issues-57/mjs.c:10195:7
    #2 0x511bbb in mjs_execute /home/eval/Desktop/mjs-issues-57/mjs.c:9296:11
    #3 0x51c780 in mjs_exec_internal /home/eval/Desktop/mjs-issues-57/mjs.c:9503:5
    #4 0x53512f in mjs_exec_file /home/eval/Desktop/mjs-issues-57/mjs.c:9526:11
    #5 0x53512f in main /home/eval/Desktop/mjs-issues-57/mjs.c:11800:11
    #6 0x7fdc65452c86 in __libc_start_main /build/glibc-CVJwZb/glibc-2.27/csu/../csu/libc-start.c:310
    #7 0x41cb89 in _start (/home/eval/Desktop/mjs-result/mjs-issues-57/mjs-bin+0x41cb89)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV /home/eval/Desktop/mjs-issues-57/mjs.c:9695:21 in mjs_parse_ffi_signature
==23415==ABORTING

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