Fix JIT TLS on MacOS 15

[arnaud-lb]

Since approximately MacOS 15, the dynamic loader changes the format of the TLV thunk, breaking our resolution code.

Here we use the new format when we detect the new loader.

This is not a regression of the new TLS resolution code. This targets 8.5, but this needs to be backported to 8.3.

Some background: https://github.com/apple-oss-distributions/dyld/blob/9307719dd8dc9b385daa412b03cfceb897b2b398/libdyld/ThreadLocalVariables.h#L46. Since MacOS 15, the dynamic loader patches the data emitted by the compiler, so that its format changes from

struct Thunk {
    void *func;
    size_t module;
    size_t offset;
}

to

struct Thunk_v2 {
     void *func;
     uint32_t module;
     uint32_t offset;
     // other fields
}

which has the same size, but not the same layout.

Possible alternative fixes:

• Disable JIT on MacOS+ZTS (it's already disabled on JIT+ZTS+Apple Silicon: Disable JIT on Apple Silicon + ZTS #13396).
• Update JIT so it uses the slower fallback on MacOS:

  php-src/ext/opcache/jit/zend_jit_ir.c

  Line 519 in 02e38fe

  jit->tls = ir_CALL(IR_ADDR, ir_CONST_FC_FUNC(zend_jit_get_tsrm_ls_cache));

• Update JIT and IR so it calls thunk->func(thunk), which has more ABI garantees that the current method, but will be slower

cc @shivammathur

[shivammathur]

@arnaud-lb
CI on macOS 15 x86_64 with this patch looks good.
https://github.com/shivammathur/php-src/actions/runs/18404705136/job/52441925613

We run 8.1 and above in the nightly CI run, so this would have to be backported to 8.1 I think.

[arnaud-lb]

I'm not sure we can fix this in 8.1 and 8.2 since these are security-fixes only. But I'm not sure what other options we have, other than skipping JIT tests (or not building JIT) on macos 15 for these versions in CI.