Add failing formatter regression for timescale CRLF comments.

Issue #2605: `//` comments after `timescale` in CRLF files fail lexical verification.

verible/verilog/formatting/formatter_test.cc

diff --git a/verible/verilog/formatting/formatter_test.cc b/verible/verilog/formatting/formatter_test.cc
index 16e0572..02853d2 100644
--- a/verible/verilog/formatting/formatter_test.cc
+++ b/verible/verilog/formatting/formatter_test.cc
@@ -21249,6 +21249,50 @@
   }
 }
 
+// Regression for https://github.com/chipsalliance/verible/issues/2605:
+// TIMESCALE_DIRECTIVE's EndOfLineComment handler used yyless(yyleng-1),
+// which left `\r` in the comment token for CRLF files. Emitting that token
+// plus a CRLF terminator produced `\r\r\n` and failed FormatEquivalent.
+TEST(FormatterEndToEndTest, TimescaleCrlfEolComment) {
+  static constexpr FormatterTestCase kTestCases[] = {
+      // Next-line `//` comment after `timescale (the reduced issue case).
+      {"`timescale 1 ps / 1 ps\r\n"
+       "// hello\r\n"
+       "module m;\r\n"
+       "endmodule\r\n",
+       "`timescale 1 ps / 1 ps\r\n"
+       "// hello\r\n"
+       "module m;\r\n"
+       "endmodule\r\n"},
+      // Same-line `//` comment on the `timescale directive.
+      {"`timescale 1 ps / 1 ps // hello\r\n"
+       "module m;\r\n"
+       "endmodule\r\n",
+       "`timescale 1 ps / 1 ps  // hello\r\n"
+       "module m;\r\n"
+       "endmodule\r\n"},
+      // LF control: this path already passed lexical verification.
+      {"`timescale 1 ps / 1 ps\n"
+       "// hello\n"
+       "module m;\n"
+       "endmodule\n",
+       "`timescale 1 ps / 1 ps\n"
+       "// hello\n"
+       "module m;\n"
+       "endmodule\n"},
+  };
+  FormatStyle style;
+  style.line_terminator = verible::LineTerminatorOptionStyle::kAuto;
+  for (const auto &test_case : kTestCases) {
+    VLOG(1) << "code-to-format:\n" << test_case.input << "<EOF>";
+    std::ostringstream stream;
+    const auto status =
+        FormatVerilog(test_case.input, "<filename>", style, stream);
+    EXPECT_OK(status) << status.message();
+    EXPECT_EQ(stream.str(), test_case.expected) << "code:\n" << test_case.input;
+  }
+}
+
 }  // namespace
 }  // namespace formatter
 }  // namespace verilog