Remove obsolete PHP_WITH_SHARED M4 macro

This is obsolete in favor of the PHP_ARG_ANALYZE macro. It was once
used in combination with the AC_ARG_WITH macro to determine whether the
extension has been configured as shared.

Author: petk

UPGRADING.INTERNALS

@@ -63,6 +63,7 @@ PHP 8.4 INTERNALS UPGRADE NOTES
    - Symbol DARWIN has been removed (use __APPLE__ to target Darwin systems).
    - Symbol MISSING_FCLOSE_DECL and M4 macro PHP_MISSING_FCLOSE_DECL removed.
    - Symbol HAVE_BSD_ICONV has been removed.
+   - M4 macro PHP_WITH_SHARED has been removed.
 
  c. Windows build system changes
    - The configure options --with-oci8-11g, --with-oci8-12c, --with-oci8-19 have

build/php.m4

@@ -965,18 +965,6 @@ dnl ---------------------------
   fi
 ])
 
-dnl
-dnl PHP_WITH_SHARED
-dnl
-dnl Checks whether $withval is "shared" or starts with "shared,XXX" and sets
-dnl $shared to "yes" or "no", and removes "shared,?" stuff from $withval.
-dnl
-AC_DEFUN([PHP_WITH_SHARED],[
-  PHP_ARG_ANALYZE_EX(withval)
-  shared=$ext_shared
-  unset ext_shared ext_output
-])
-
 dnl
 dnl PHP_ADD_EXTENSION_DEP(extname, depends [, depconf])
 dnl