[clang-format] Single-quote separator from C23 leads to wrong formatting

[goekce]

clang-format version 22.0.0 (/build/llvm-git/llvm-project cdd54ff927e0207a3e65bade576e3c2511112953)

test.c:

char data = 0b1000'0110; // Single quotation mark for better readability

int main(void) {
  return 0;
}

clang-format test.c results in:

char data = 0b1000'0110; // Single quotation mark for better readability

    int
    main(void) { // <= expectation: `int main...`
  return 0;
}

according to clangd/clangd#2485 (comment), this is a regression in clang-format 20 compared to clang-format 19.

[llvmbot]

@llvm/issue-subscribers-clang-format

Author: Gökçe Aydos (goekce)

``` clang-format version 22.0.0 (/build/llvm-git/llvm-project cdd54ff) ```

test.c:

char data = 0b1000'0110; // Single quotation mark for better readability

int main(void) {
  return 0;
}

clang-format test.c results in:

char data = 0b1000'0110; // Single quotation mark for better readability

    int
    main(void) { // <= expectation: `int main...`
  return 0;
}

according to clangd/clangd#2485 (comment), this is a regression in clang-format 20 compared to clang-format 19.

[owenca]

/cherry-pick 30f4781

[llvmbot]

/pull-request #158512