This patch adds missing newlines, trims multiple redundant final
newlines into a single one, and trims redundant leading newlines in all
*.phpt sections.

According to POSIX, a line is a sequence of zero or more non-' <newline>'
characters plus a terminating '<newline>' character. [1] Files should
normally have at least one final newline character.

C89 [2] and later standards [3] mention a final newline:
"A source file that is not empty shall end in a new-line character,
which shall not be immediately preceded by a backslash character."

Although it is not mandatory for all files to have a final newline
fixed, a more consistent and homogeneous approach brings less of commit
differences issues and a better development experience in certain text
editors and IDEs.

[1] http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_206
[2] https://port70.net/~nsz/c/c89/c89-draft.html#2.1.1.2
[3] https://port70.net/~nsz/c/c99/n1256.html#5.1.1.2

EXPECTF logic in run-tests.php is considerable, so let's avoid it.

* Commands are not properly escaped for windows
* Specifying "-n" to check loaded modules causes "Module already loaded"
warning
* Extensions to be loaded need the "php_" prefix on Windows

Bug: https://bugs.php.net/bug.php?id=75042

Add back -n flag to fetch loaded extensions in run-tests.php

Add test for phpt EXTENSIONS directive

Add a second test for bug 75042

Add test to test loading of nonexistent shared module

with the EXTENSIONS phpt block

Pass ini settings when checking loaded extensions

This fail has nothing together with any changes in run-tests.php
Using run-tests.php from the 5.5 branch brings the same result. So
merely it is about how PHP7 handles and buffers errors.