Switch from _ to * for wildcard pattern

This avoids a BC break, and/or incompatibilities with _ named types.

Author: iluuu1994

Zend/tests/numeric_literal_separator_002.phpt

@@ -5,4 +5,4 @@ Invalid use: trailing underscore
 100_;
 ?>
 --EXPECTF--
-Parse error: syntax error, unexpected token "_" in %s on line %d
+Parse error: syntax error, unexpected identifier "_" in %s on line %d

Zend/tests/numeric_literal_separator_004.phpt

@@ -5,4 +5,4 @@ Invalid use: underscore left of period
 100_.0;
 ?>
 --EXPECTF--
-Parse error: syntax error, unexpected token "_" in %s on line %d
+Parse error: syntax error, unexpected identifier "_" in %s on line %d

Zend/tests/pattern_matching/is/underscore_bc.phpt

@@ -5,13 +5,13 @@ Wildcard pattern matching
 
 class Foo {}
 
-var_dump('' is _);
-var_dump(42 is _);
-var_dump(3.141 is _);
-var_dump(null is _);
-var_dump(true is _);
-var_dump(new Foo() is _);
-var_dump([1, 2, 3] is _);
+var_dump('' is *);
+var_dump(42 is *);
+var_dump(3.141 is *);
+var_dump(null is *);
+var_dump(true is *);
+var_dump(new Foo() is *);
+var_dump([1, 2, 3] is *);
 
 ?>
 --EXPECT--

Zend/tests/pattern_matching/is/wildcard.phpt

@@ -55,7 +55,7 @@ var_dump(match ('Foo') {
     is 1 => wrong(),
     is 2 => wrong(),
     is 3 => wrong(),
-    is _ => 'Wildcard pattern',
+    is * => 'Wildcard pattern',
 });
 
 var_dump(match (15) {

Zend/tests/pattern_matching/match/basic.phpt

@@ -136,7 +136,6 @@ static YYSIZE_T zend_yytnamerr(char*, const char*);
 %token <ident> T_DEFAULT       "'default'"
 %token <ident> T_MATCH         "'match'"
 %token <ident> T_IS            "'is'"
-%token <ident> T_UNDERSCORE    "'_'"
 %token <ident> T_BREAK         "'break'"
 %token <ident> T_CONTINUE      "'continue'"
 %token <ident> T_GOTO          "'goto'"
@@ -312,7 +311,7 @@ reserved_non_modifiers:
 	| T_FUNCTION | T_CONST | T_RETURN | T_PRINT | T_YIELD | T_LIST | T_SWITCH | T_ENDSWITCH | T_CASE | T_DEFAULT | T_BREAK
 	| T_ARRAY | T_CALLABLE | T_EXTENDS | T_IMPLEMENTS | T_NAMESPACE | T_TRAIT | T_INTERFACE | T_CLASS
 	| T_CLASS_C | T_TRAIT_C | T_FUNC_C | T_METHOD_C | T_LINE | T_FILE | T_DIR | T_NS_C | T_FN | T_MATCH | T_ENUM
-	| T_UNDERSCORE | T_IS
+	| T_IS
 ;
 
 semi_reserved:
@@ -1298,7 +1297,7 @@ atomic_pattern:
 	|	array_pattern { $$ = $1; }
 	|	binding_pattern { $$ = $1; }
 	|	class_const_pattern { $$ = $1; }
-	|	T_UNDERSCORE { $$ = zend_ast_create(ZEND_AST_WILDCARD_PATTERN); }
+	|	'*' { $$ = zend_ast_create(ZEND_AST_WILDCARD_PATTERN); }
 	|	'(' pattern ')' {
 			$$ = $2;
 			if ($$->kind == ZEND_AST_OR_PATTERN || $$->kind == ZEND_AST_AND_PATTERN) {

Zend/zend_language_parser.y

@@ -1509,14 +1509,6 @@ OPTIONAL_WHITESPACE_OR_COMMENTS ({WHITESPACE}|{MULTI_LINE_COMMENT}|{SINGLE_LINE_
 	RETURN_TOKEN_WITH_IDENT(T_IS);
 }
 
-<ST_IN_SCRIPTING>"_"[ \t\r\n]*"(" {
-	yyless(1);
-	RETURN_TOKEN_WITH_STR(T_STRING, 0);
-}
-<ST_IN_SCRIPTING>"_" {
-	RETURN_TOKEN_WITH_IDENT(T_UNDERSCORE);
-}
-
 <ST_IN_SCRIPTING>"endswitch" {
 	RETURN_TOKEN_WITH_IDENT(T_ENDSWITCH);
 }

Zend/zend_language_scanner.l

@@ -242,11 +242,6 @@
  * @cvalue T_IS
  */
 const T_IS = UNKNOWN;
-/**
- * @var int
- * @cvalue T_UNDERSCORE
- */
-const T_UNDERSCORE = UNKNOWN;
 /**
  * @var int
  * @cvalue T_BREAK