OOB memory error in wasm32

[straight-shoota]

In #13844 the wasm32 spec fails.

Error: failed to run main module `wasm32_std_spec.wasm`

Caused by:
    0: failed to invoke command default
    1: error while executing at wasm backtrace:
           0: 0x1fed53 - <unknown>!dlmalloc
           1: 0x200db0 - <unknown>!realloc
           2: 0xa3818 - realloc
                           at /home/johannes/src/crystal-lang/crystal/src/gc/none.cr:21:5
           3: 0xa3804 - __crystal_realloc64
                           at /home/johannes/src/crystal-lang/crystal/src/gc.cr:46:3
           4: 0x15642e - realloc
                           at /home/johannes/src/crystal-lang/crystal/src/pointer.cr:359:18
           5: 0x155a73 - realloc_entries
                           at /home/johannes/src/crystal-lang/crystal/src/hash.cr:910:16
           6: 0x154950 - resize
                           at /home/johannes/src/crystal-lang/crystal/src/hash.cr:589:7
           7: 0x153c3b - upsert
                           at /home/johannes/src/crystal-lang/crystal/src/hash.cr:378:11
           8: 0x15330e - []=
                           at /home/johannes/src/crystal-lang/crystal/src/hash.cr:1050:5
           9: 0x71ece - ~HTML::SINGLE_CHAR_ENTITIES:init
                           at /home/johannes/src/crystal-lang/crystal/src/html/entities.cr:3:26
          10: 0x1da3 - __crystal_main
                           at /home/johannes/src/crystal-lang/crystal/src/html/entities.cr:3:3
          11: 0x1fe43c - main_user_code
                           at /home/johannes/src/crystal-lang/crystal/src/crystal/main.cr:129:5
          12: 0xbbf71 - main
                           at /home/johannes/src/crystal-lang/crystal/src/crystal/main.cr:115:7
          13: 0xbbf37 - main
                           at /home/johannes/src/crystal-lang/crystal/src/crystal/main.cr:141:3
          14: 0xbc029 - __main_argc_argv
                           at /home/johannes/src/crystal-lang/crystal/src/crystal/system/wasi/main.cr:32:3
          15: 0x201946 - <unknown>!__main_void
          16: 0xbbfd8 - _start
                           at /home/johannes/src/crystal-lang/crystal/src/crystal/system/wasi/main.cr:25:12
    2: memory fault at wasm address 0x73657268 in linear memory of size 0x70000
    3: wasm trap: out of bounds memory access

Considering that the code works flawlessly in other backends, there seems to be an error in the wasm32 integration.

Originally posted by @straight-shoota in #13844 (comment)

[straight-shoota]

A branch with this error reproduction and some bug reconnaissance is available here: https://github.com/straight-shoota/crystal/tree/test/html-unescape-wasm32

[straight-shoota]

A similar issue was noticed on #14067 (comment)

https://github.com/crystal-lang/crystal/actions/runs/7128256420/job/19410152386