Add CRLF test case for EregToPregMatchRector

[mcenirm]

EregToPregMatchRector (and EregToPcreTransformer) convert ereg regular expression strings that contain CR or LF characters (i.e., double-quoted strings with \r or \n) to preg regular expression strings that are single-quoted but contain the unescaped character (i.e., multi-line string literal with embedded CR or LF characters).

Example:

    $splitLF   = split("\n",   $s);
    $splitCRLF = split("\r\n", $s);

... becomes ...

    $splitLF   = preg_split('#
#m',   $s);
    $splitCRLF = preg_split('#
#m', $s);

(The CR is invisible in the second statement in the output, so it looks like a duplicate of the first statement.)

This transformation complies with PHP syntax, and the preg functions treat "#\r#" as equivalent to '#\r#'. The problem occurs when git and its autocrlf behavior removes CR characters without regard to them being embedded in multi-line strings. This results in a platform-dependent regular expression, when the original source code avoided that behavior.

Even though this is clearly a caveat developer situation, it would be nice if the EregToPregMatchRector rule could try to preserve the original representation. Converting the double-quoted string to a suitable single-quoted PCRE regular expression would be ideal, but probably too error prone.

[samsonasik]

I cherry-picked your commit at PR :

• [Php70] Fix with \r\n on EregToPregMatchRector #6246