[clang-format] instanceof is a keyword only in Java/JavaScript (#88085)

Fixes #87907.

Author: owenca

clang/lib/Format/TokenAnnotator.cpp

@@ -2354,7 +2354,8 @@ class AnnotatingParser {
     // Line.MightBeFunctionDecl can only be true after the parentheses of a
     // function declaration have been found. In this case, 'Current' is a
     // trailing token of this declaration and thus cannot be a name.
-    if (Current.is(Keywords.kw_instanceof)) {
+    if ((Style.isJavaScript() || Style.Language == FormatStyle::LK_Java) &&
+        Current.is(Keywords.kw_instanceof)) {
       Current.setType(TT_BinaryOperator);
     } else if (isStartOfName(Current) &&
                (!Line.MightBeFunctionDecl || Current.NestingLevel != 0)) {

clang/unittests/Format/TokenAnnotatorTest.cpp

@@ -1769,6 +1769,10 @@ TEST_F(TokenAnnotatorTest, UnderstandsFunctionDeclarationNames) {
   EXPECT_TOKEN(Tokens[3], tok::identifier, TT_Unknown);
   EXPECT_TOKEN(Tokens[4], tok::l_paren, TT_FunctionTypeLParen);
 
+  Tokens = annotate("void instanceof();");
+  ASSERT_EQ(Tokens.size(), 6u);
+  EXPECT_TOKEN(Tokens[1], tok::identifier, TT_FunctionDeclarationName);
+
   Tokens = annotate("int iso_time(time_t);");
   ASSERT_EQ(Tokens.size(), 7u) << Tokens;
   EXPECT_TOKEN(Tokens[1], tok::identifier, TT_FunctionDeclarationName);