Analogously to JS_WriteObject2, it allows the user to get a tab with all
the SAB objects that were read.
This can help adjust reference counts in a scenario where a SAB that was
written increased it and it's necessary to decrease it upon reading it.
Complains in the post-ckeckout step:
```
Post job cleanup.
/usr/bin/docker exec f32fc88d37a181d710e2802cbad0646c9780efe4af35a093fe68d09d8201a74e sh -c "cat /etc/*release | grep ^ID"
/__e/node20/bin/node: /lib/x86_64-linux-gnu/libc.so.6: version `GLIBC_2.28' not found (required by /__e/node20/bin/node)
```
This avoids the two GCC -Wconversion warnings in this public header, which is useful when using extensive error reporting from the compiler, and treating warnings as errors.
- no longer pass the array length to `utf8_decode`
- add `utf8_decode_len` for border cases
- use switch based dispatch in `utf8_decode_len` to work around a gcc 12.2 optimizer bug
integer conversions:
- improve `u32toa_radix` and `u64toa_radix`, add `i32toa_radix`
- use `i32toa_radix` for small ints in `js_number_toString`
floating point conversions (`js_dtoa`):
- complete rewrite with fewer calls to `snprintf`
- remove `JS_DTOA_FORMAT`, define 4 possible modes for `js_dtoa`
- remove the radix argument in `js_dtoa`
- merge `js_dtoa1` into `js_dtoa`
- add `js_dtoa_infinite` for non finite values
- simplify sign handling
- handle locale specific decimal point transparently
helper function `js_fcvt`:
- simplify `js_fcvt`, remove `js_fcvt1`, reduce overhead
- round up manually instead of using `fesetround(FE_UPWARD)`.
helper function `js_ecvt`:
- document `js_ecvt` and `js_ecvt1` behavior
- avoid redundant `js_ecvt1` calls in `js_ecvt`
- fixed buffer contents, no buffer copies
- simplify decimal point handling
- round up manually instead of using `fesetround(FE_UPWARD)`.
miscellaneous:
- remove `CONFIG_PRINTF_RNDN`. This fixes some of the conversion errors
on Windows. Updated the tests accordingly
- this fixes a v8.sh bug on macOS: `0.5.toFixed(0)` used to produce `0` instead of `1`
- add regression tests, update test_conv unit tests
- add benchmarks for `toFixed`, `toPrecision` and `toExponential` number methods
- benchmarks show all conversions are now 40 to 45% faster (M2)
- use single test in `js_strtod` loop.
- use more explicit `ATOD_xxx` flags
- remove `ATOD_TYPE_MASK`, use `ATOD_WANT_BIG_INT` instead
- remove unused arguments `flags` and `pexponent` in `js_string_to_bigint`
- merge `js_atof` and `js_atof2`, remove `slimb_t *pexponent` argument
- simplify and document `js_atof` parser, remove cumbersome labels,
- simplify `js_parseInt` test for zero radix for `ATOD_ACCEPT_HEX_PREFIX`
- simplify `next_token` number parsing, handle legacy octal in parser only
- simplify `JS_StringToBigInt`, use flags only.
- remove unused `slimb_t exponent` token field
- add number syntax tests
