The fix for bug #78241 assumed that `time_t` would always be 64bit, but
actually is 32bit for x86.  We therefore enforce 64bit arithmetic to
avoid wrapping.

- Checks and defines are not relevant for files that include it anymore
- Some code is not used anymore
- Defines are a bit duplicated in zend_portability.h and TSRM.h file
- MAXPATHLEN defs moved to zend_virtual_cwd.h

There is also a php_strtok_r() function, which is actually used,
but nothing uses the tsrm_strtok_r() variant...

The tsrm_config.w32.h file is a simple wrapper for already defined
symbols and includes elsewhere.

Closes GH-4383

This simplifies TSRM build steps a bit and avoids doing unnecessary
steps:
- The `PTHREADS_CHECK_COMPILE` can called inside the for loops only
  since this is only where the `$pthreads_checked` variable is used.
- Assigning variables can be then done only in the configure.ac
  once.
- use `m4_include()` instead of the `sinclude()` in the middle of
  the build steps.
- The `$threads_result` variable is not used in the code or in
  extensions.

* PHP-7.3:
  Fix #78241: touch() does not handle dates after 2038 in PHP 64-bit

* PHP-7.2:
  Fix #78241: touch() does not handle dates after 2038 in PHP 64-bit

`time_t` defaults to `_time64` (which is 64bit signed) even on x86, but
`Int32x32To64()` truncates it to signed 32bit.  We replace the macro
with the "manual" calculation.

- checking for beos systems is no longer relevant in configure.ac
- usage of undefined constant BETHREADS removed.

Closes GH-4346

This macro is not needed anymore. The AC_PROG_CC is done in the main
configure.ac file and the ranlib check is done by the bundled libtool
macros.

Closes GH-4339