Style checker shouldn't complain about requires (MyConcept)

https://bugs.webkit.org/show_bug.cgi?id=274324
rdar://128284081

Reviewed by Jonathan Bedard.

Right now the style checker will complain about an extra space before the
arguments to a function call when you do `requires (MyConcept)`. We should
treat spaces after `requires` the same way we treat spaces after other keywords.

* Tools/Scripts/webkitpy/style/checkers/cpp.py:
(check_spacing_for_function_call):
* Tools/Scripts/webkitpy/style/checkers/cpp_unittest.py:
(WebKitStyleTest.test_spacing):

Canonical link: https://commits.webkit.org/278922@main

Tools/Scripts/webkitpy/style/checkers/cpp.py

@@ -1620,8 +1620,8 @@ def check_spacing_for_function_call(line, line_number, file_state, error):
     # " (something)[something]"
     # Note that we assume the contents of [] to be short enough that
     # they'll never need to wrap.
-    if (  # Ignore control structures.
-        not search(r'\b(if|for|while|switch|return|new|delete)\b', function_call)
+    if (  # Ignore control structures / c++20 concept constraints.
+        not search(r'\b(if|for|while|switch|return|new|delete|requires)\b', function_call)
         # Ignore lambda functions
         and not regex_for_lambdas_and_blocks(function_call, line_number, file_state, error)
         # Ignore pointers/references to functions.

Tools/Scripts/webkitpy/style/checkers/cpp_unittest.py

@@ -5000,6 +5000,17 @@ def test_spacing(self):
             ['Extra space after ( in function call  [whitespace/parens] [4]',
              'Extra space before )  [whitespace/parens] [2]'])
 
+        # Ignore concept constraints.
+        self.assert_multi_line_lint(
+            'template<typename T>\n'
+            'requires (MyConcept<T>)\n'
+            'int f(T a);',
+            '')
+
+        self.assert_multi_line_lint(
+            'int foo(int a, int b) requires (MyConcept<T>) { return a + b; }',
+            '')
+
         # Ignore spacing inside four char code.
         self.assert_multi_line_lint(
             'CTFontTableTag os2Tag = \'OS/2\';',