Description:
------------
When building a PHP extension on AIX, I am unable to run tests. Here's the output I get (building ibm_db):

-bash-4.4$ make test

Build complete.
Don't forget to run 'make test'.

/bin/sh: line 12: .: /QOpenSys/home/kadler/ibm_db2_73/modules/ibm_db2.so: cannot execute binary file
PHP Warning:  PHP Startup: Unable to load dynamic library '' (tried: /QOpenSys/home/kadler/ibm_db2_73/modules/ (Invalid argument), /QOpenSys/home/kadler/ibm_db2_73/modules/.so (Could not load module /QOpenSys/home/kadler/ibm_db2_73/modules/.so.
System error: No such file or directory)) in Unknown on line 0
PHP Warning:  PHP Startup: Unable to load dynamic library '' (tried: /QOpenSys/home/kadler/ibm_db2_73/modules/ (Invalid argument), /QOpenSys/home/kadler/ibm_db2_73/modules/.so (Could not load module /QOpenSys/home/kadler/ibm_db2_73/modules/.so.
System error: No such file or directory)) in Unknown on line 0

=====================================================================
PHP         : /QOpenSys/pkgs/bin/php 
Warning: PHP Startup: Unable to load dynamic library '' (tried: /QOpenSys/home/kadler/ibm_db2_73/modules/ (Invalid argument), /QOpenSys/home/kadler/ibm_db2_73/modules/.so (Could not load module /QOpenSys/home/kadler/ibm_db2_73/modules/.so.
System error: No such file or directory)) in Unknown on line 0

PHP_SAPI    : cli
PHP_VERSION : 7.3.1
ZEND_VERSION: 3.3.1
PHP_OS      : OS400 - OS400 wernstrom 2 7 0010000ACBAA
INI actual  : /QOpenSys/home/kadler/ibm_db2_73/tmp-php.ini
More .INIs  :   
---------------------------------------------------------------------


This is due to how the Makefile is generated on AIX. The code to load the test extensions reads in the dlname from the libtool.la file:

PHP_TEST_SHARED_EXTENSIONS =  ` \
        if test "x$(PHP_MODULES)" != "x"; then \
                for i in $(PHP_MODULES)""; do \
                        . $$i; $(top_srcdir)/build/shtool echo -n -- " -d extension=$$dlname"; \
                done; \
        fi; \
        if test "x$(PHP_ZEND_EX)" != "x"; then \
                for i in $(PHP_ZEND_EX)""; do \
                        . $$i; $(top_srcdir)/build/shtool echo -n -- " -d $(ZEND_EXT_TYPE)=$(top_builddir)/modules/$$dlname"; \
                done; \
        fi`


However, on AIX PHP_MODULES is set to a bare .so:

PHP_MODULES = $(phplibdir)/ibm_db2.so


Above output shows results for 7.3, but the problem goes back to PHP 5.6 (at least).