build,ci: add ASAN build to CI

[saghul]

No description provided.

[saghul]

./build/tjs test tests/
Uninitialized bytes in __interceptor_strlen at offset 11 inside [0x70400000136f, 12)
==7999==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x560ba9a2af88 in JS_NewAtom /home/runner/work/txiki.js/txiki.js/deps/quickjs/quickjs.c:2925:36
    #1 0x560ba9a39a3f in JS_DefinePropertyValueStr /home/runner/work/txiki.js/txiki.js/deps/quickjs/quickjs.c:9341:12
    #2 0x560ba9a2883f in JS_AddIntrinsicBaseObjects /home/runner/work/txiki.js/txiki.js/deps/quickjs/quickjs.c:47955:9
    #3 0x560ba9a277e9 in JS_NewContext /home/runner/work/txiki.js/txiki.js/deps/quickjs/quickjs.c:2120:5
    #4 0x560ba99bd60a in TJS_NewRuntimeInternal /home/runner/work/txiki.js/txiki.js/src/vm.c:167:16
    #5 0x560ba99bd2a9 in TJS_NewRuntime /home/runner/work/txiki.js/txiki.js/src/vm.c:146:12
    #6 0x560ba98feec0 in main /home/runner/work/txiki.js/txiki.js/src/cli.c:33:23
    #7 0x7fa4f9c29d8f  (/lib/x86_64-linux-gnu/libc.so.6+0x29d8f) (BuildId: c289da5071a3399de893d2af81d6a30c62646e1e)
    #8 0x7fa4f9c29e3f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e3f) (BuildId: c289da5071a3399de893d2af81d6a30c62646e1e)
    #9 0x560ba98780b4 in _start (/home/runner/work/txiki.js/txiki.js/build/tjs+0x440b4) (BuildId: ce71f2d095832f148ef0d0d00dce3fcc312cd172)

SUMMARY: MemorySanitizer: use-of-uninitialized-value /home/runner/work/txiki.js/txiki.js/deps/quickjs/quickjs.c:2925:36 in JS_NewAtom
Exiting
make: *** [Makefile:115: test] Error 1

Well, that's a fun one.

@bnoordhuis Any idea why this can fail here?

[saghul]

This is weird. If I enable the flags wholesale, now things fail in new and mysterious ways...