Update libtool to newer version

CONTRIBUTING.md

@@ -176,6 +176,7 @@ locations.
     ├─ config.guess                 # https://git.savannah.gnu.org/cgit/config.git
     ├─ config.sub                   # https://git.savannah.gnu.org/cgit/config.git
     ├─ libtool.m4                   # https://git.savannah.gnu.org/cgit/libtool.git
+    ├─ lt*.m4                       # https://git.savannah.gnu.org/cgit/libtool.git
     ├─ ltmain.sh                    # https://git.savannah.gnu.org/cgit/libtool.git
     ├─ pkg.m4                       # https://gitlab.freedesktop.org/pkg-config/pkg-config
     ├─ shtool                       # https://www.gnu.org/software/shtool/

README.md

@@ -49,7 +49,7 @@ sudo apt install -y pkg-config build-essential autoconf bison re2c libxml2-dev l
 On Fedora, you can install these using:
 
 ```shell
-sudo dnf install re2c bison autoconf make libtool ccache libxml2-devel sqlite-devel
+sudo dnf install re2c bison autoconf make ccache libxml2-devel sqlite-devel
 ```
 
 On MacOS, you can install these using `brew`:

UPGRADING.INTERNALS

@@ -89,6 +89,14 @@ PHP 8.6 INTERNALS UPGRADE NOTES
     zend_enum_fetch_case_id(zend_object*).
 
 - Unix build system changes:
+  . scripts/dev/update-autoconf.sh has been added to update config.*/libtool.
+  . libtool has been upgraded to 2.5.4 (serial 63), which fixes many bugs.
+  . As part of the upgrade to the new libtool:
+    . libtool is now spread across multiple files. phpize has been updated to
+      handle this.
+    . On macOS, libtool now uses -undefined dynamic_lookup for shared objects,
+      instead of -undefined suppress -flat_namespace.
+    . --with-pic is now --enable-pic. The old flag will result in an error.
   . Symbol HAVE_ST_BLOCKS has been removed from php_config.h (use
     HAVE_STRUCT_STAT_ST_BLOCKS).
 

Zend/Zend.m4

@@ -118,7 +118,7 @@ dnl Ugly hack to check if dlsym() requires a leading underscore in symbol name.
 dnl
 AC_DEFUN([ZEND_DLSYM_CHECK], [dnl
 AC_MSG_CHECKING([whether dlsym() requires a leading underscore in symbol names])
-_LT_AC_TRY_DLOPEN_SELF([AC_MSG_RESULT([no])], [
+_LT_TRY_DLOPEN_SELF([AC_MSG_RESULT([no])], [
   AC_MSG_RESULT([yes])
   AC_DEFINE([DLSYM_NEEDS_UNDERSCORE], [1],
     [Define to 1 if 'dlsym()' requires a leading underscore in symbol names.])