Remove useless PHPDBG_* constants

The sole purpose of `PHPDBG_FILE`, `PHPDBG_METHOD`, `PHPDBG_LINENO` and
`PHPDBG_FUNC` has been to be passed as first argument to `phpdbg_break`.
However, this functions is replaced as of PHP 5.6.3 by
`phpdbg_break_file`, `phpdbg_break_method` and 'phpdbg_break_func`,
respectively.  Therefore, we're finally removing the useless constants.

Author: cmb69

UPGRADING

@@ -163,6 +163,10 @@ Standard:
 3. Changes in SAPI modules
 ========================================
 
+phpdbg:
+  . The unused constants PHPDBG_FILE, PHPDBG_METHOD, PHPDBG_LINENO and
+    PHPDBG_FUNC have been removed.
+
 ========================================
 4. Deprecated Functionality
 ========================================

sapi/phpdbg/phpdbg.c

@@ -210,11 +210,6 @@ static PHP_MINIT_FUNCTION(phpdbg) /* {{{ */
 
 	REGISTER_STRINGL_CONSTANT("PHPDBG_VERSION", PHPDBG_VERSION, sizeof(PHPDBG_VERSION)-1, CONST_CS|CONST_PERSISTENT);
 
-	REGISTER_LONG_CONSTANT("PHPDBG_FILE",   FILE_PARAM, CONST_CS|CONST_PERSISTENT);
-	REGISTER_LONG_CONSTANT("PHPDBG_METHOD", METHOD_PARAM, CONST_CS|CONST_PERSISTENT);
-	REGISTER_LONG_CONSTANT("PHPDBG_LINENO", NUMERIC_PARAM, CONST_CS|CONST_PERSISTENT);
-	REGISTER_LONG_CONSTANT("PHPDBG_FUNC",   STR_PARAM, CONST_CS|CONST_PERSISTENT);
-
 	REGISTER_LONG_CONSTANT("PHPDBG_COLOR_PROMPT", PHPDBG_COLOR_PROMPT, CONST_CS|CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("PHPDBG_COLOR_NOTICE", PHPDBG_COLOR_NOTICE, CONST_CS|CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("PHPDBG_COLOR_ERROR",  PHPDBG_COLOR_ERROR, CONST_CS|CONST_PERSISTENT);