pcre2_jit_stack_free (3) - Linux Man Pages
pcre2_jit_stack_free: Perl-compatible regular expressions (revised API)
PCRE2 - Perl-compatible regular expressions (revised API)
This function is used to free a JIT stack that was created by pcre2_jit_stack_create() when it is no longer needed. If the argument is NULL, the function returns immediately without doing anything. For more details, see the pcre2jit page.
There is a complete description of the PCRE2 native API in the pcre2api page and a description of the POSIX API in the pcre2posix page.