[clang] [clang-format] Handle doxygen commands starting with \ (PR #80381)

[Owen Pan via cfe-commits]

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@@ -1909,6 +1909,14 @@ TEST_F(FormatTestComments, ReflowsComments) {
                    "// @param arg",
                    getLLVMStyleWithColumns(20)));
 
+  // Don't reflow lines starting with '\'.
+  EXPECT_EQ("// long long long\n"
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owenca wrote:

Can you use `verifyFormat` or `verifyNoChange` instead?

https://github.com/llvm/llvm-project/pull/80381